I mentioned in an earlier post that I felt as if I wanted to share my experiences after having written five books, and been a minor co-author on a sixth.
First, I wanted to share a bit about my history of how I got involved in writing books, just to give you some perspective. I didn't start writing books; instead, I started reviewing books and book proposals. This seemed like a great way to see what was up and coming in the industry, as well as to make a little mad money on the side (or, if the remuneration was books, to stock my library). At one point, I was working on a review and completely disagreed with something the authors stated with respect to NTFS alternate data streams; not only did I disagree with it, but I offered up some text of what I thought the section should say. In the end, the authors agreed and accepted my contribution.
When the book was published, the publisher asked the authors if they knew of anyone who might be interested in writing a book. My name was offered up along with several others, and I accepted...and began the process of discovery that has led me to this point.
Further, I do have a long history of writing, albeit not books. Like many of us, I have a public school education. 'Nuff said, right? I wrote in college. I wrote during my first career as a military officer. I wrote a thesis for my graduate degree. I have written a lot of reports since I got out of the military and began pursing a career in the information security field. I can't say that I've enjoyed all of the writing, but it does provide both breadth and depth to my writing experience. In every case, there's some bad stuff that I didn't like and leave behind, and in most cases, there are some gems that have really benefited me that I can trace back to some of that early experience.
What I'd like to do now is provide something of a process but really more of my experiences and what I've learned in the process of writing books. My hope is that someone will take a look at this and perhaps decide to pick up their pen, as it were, and put it to paper. I know that there are some really smart folks out there with some really good ideas that need to be shared, and writing a book is a great way to do that.
Why write a book?
The first thing you need to think about is, why do you want to write a book? Some folks I have met want to write a book so that home users know what to do to secure their systems, or the members of their church know more about the Internet in general. Personally, I wanted to take all that stuff I had laying around in different locations and put it in one place...yes, that's right, I use my own book as a reference. ;-) After my first book, I wanted to prove to myself that I wasn't a one-trick pony and that this was something I could do again.
If you're in a technical field, do not expect to get rich writing a book, or even several books..so that's not a reason to write a book. It just it's going to happen. The technical field does not have the market that other genres tend to enjoy; in fact, the more technical and narrowly focused your book, the more of a niche market you'll be focused on and the less likely you will be to really "score".
There can be a number of reasons to write a book...those that I've mentioned above are just some of them. However, if you don't have a good reason or a goal that you'd like to reach, what's going to keep you going through the process?
Choose a topic
So, what do you want to write about? Clearly, if you're reading this blog, then you're interested in technical topics, including incident response and/or digital forensics. Okay, that's a good place to start. Can you narrow it down...or should you? Sometimes, taking a broad brush approach is a great way to get started on a topic. I've found that focusing very narrowly has proven to be the way to go for what I'm writing about...the narrow focus being forensic analysis of Windows systems.
However, I don't think that this process is really specific to just technical books. I think a lot of my experiences in writing books can be applied to other areas/genres, as well...such as writing children's books.
Research the topic
Look online and at bookstores to see if there are any current books that cover your chosen topic. If there are, you would have to determine how you would differentiate your book from the others. Will your book be more up-to-date, will you provide a different perspective somehow?
If there aren't any other books or resources that cover what you're interested in writing about...you may be home free.
Another aspect of this research what will benefit you greatly is to take a look at other resources, and not just those related to your chosen topic. Look at books in your chosen genre that you've enjoyed reading, and try to determine what it is you really enjoyed about them. One early example that I found that I really enjoyed is sidebars, little snippets that usually appear on the page in a grey box that tend to pertain to what you're currently reading, even if only tangentially. I recently reviewed the Malware Analyst's Cookbook, and I really like the idea of "recipes".
Create a detailed outline
Before you begin writing your book, outline it. Yes, just like you learned in grade school...and you thought you'd never use that again, like math. Begin with a simple outline, and begin adding to it. This allows you to begin to organize your thoughts with respect to writing your book, and begin preparing for the questions you're going to eventually encounter, such as how many chapters your book will have, what topics it will cover, etc. When I've put together outlines, I've found that just the act of writing the outline has led me to the idea that my chapters need to be restructured to make better sense, and that I needed to add additional chapters, as well.
A detailed outline helps me to organize my thoughts, and see where I need to include images, charts, figures, tables, etc. Would an image here make really good sense, and would a table here that encapsulates and summarizes the last three paragraphs really be useful to the reader?
Adding detail to your outline will only benefit you in the long run. Having a detailed outline keeps you on-point and on-track, provides some structure to what you're doing while you're doing it, and can be very beneficial, particularly if you've taken additional notes and written down some choice phrases that you'd like to use.
Just so you know, both publishers I've worked with thus far have asked for this research and work (i.e., outline) to be done and submitted as part of a proposal before going forward. So, you're going to *have* to do the work, and as much as I didn't want to do it the first time, I found out that going through the process...I mean, really going through it, not just doing it to get it done...made a difference.
Seek review
Most of us in the technical field do not like to have our written matter (when we do it) reviewed. I know that. You know it, too. But know that as you begin going down this road, you're going to get tunnel vision and you won't see the forest for the trees. To use another cliche and score a hat trick, you'll be too far down in the weeds and you'll need a reality check. Find someone you trust to give you honest, thoughtful criticism. When I was writing my very first book, I got a lot of that kind of criticism from Jennifer Kolde, and I've used what I learned through our exchanges to try and improve my writing with each book. As much as you won't want to, it will only benefit you to find someone (or someones, plural) to take a look at your ideas and give you a reality check.
Know that it will suck
That's right...simply accept the fact that this will be hard. Why? If you choose to write a book, you're going to have to write, which means you'll be adding a new activity that is going to replace an old activity in your life. You may have to give something up...at least, in part. My lovely wife, God bless her, says that when I was writing my first book, she had no idea that I was writing a book. That was because I rarely gave up our dates during that process...instead, taking her to dinner or a comedy show served as a much needed break.
Also, the truth is, most people don't like to write, especially technical people. Case notes, reports, you name it...most technical folks simply do not enjoy the act of writing.
However, with a little (okay, a lot) prior planning, you can make the process of writing a book much easier.
Friday, December 17, 2010
Thursday, December 16, 2010
Convergence
At the BasisTech Open Source conference (June, 2010), a LEO told me, "we do CP and fraud cases, you do intrusions and malware."
My response at the time was, well, no, we (meaning analysts/examiners who are not LE) solve problems...and the people who call us have intrusion and malware issues. My point was that much of what we do and the skills we bring to the table are (or could be) very useful to LE. In fact, many of us who are not LE have done work on CP cases, some even resulting in plea agreements.
Looking back over some of the work that I and others have done, it occurs to me that there's an ever greater convergence between LE and analysts in the private sector. Say LE has a CP or fraud case...if the claim of "the Trojan did it" is made, then the case becomes a malware case, even to the point that the claim has to be disproved. If the claim is made that an unauthorized user accessed the system and placed the image files on the system, then the case then becomes an intrusion case.
So I guess my point is that there's a convergence in what each of us does, and we're not quite so separate and in our own silos the way some think, and we don't so much have disparate skill sets. I'm just sayin'...
My response at the time was, well, no, we (meaning analysts/examiners who are not LE) solve problems...and the people who call us have intrusion and malware issues. My point was that much of what we do and the skills we bring to the table are (or could be) very useful to LE. In fact, many of us who are not LE have done work on CP cases, some even resulting in plea agreements.
Looking back over some of the work that I and others have done, it occurs to me that there's an ever greater convergence between LE and analysts in the private sector. Say LE has a CP or fraud case...if the claim of "the Trojan did it" is made, then the case becomes a malware case, even to the point that the claim has to be disproved. If the claim is made that an unauthorized user accessed the system and placed the image files on the system, then the case then becomes an intrusion case.
So I guess my point is that there's a convergence in what each of us does, and we're not quite so separate and in our own silos the way some think, and we don't so much have disparate skill sets. I'm just sayin'...
Monday, December 13, 2010
Book Review: Malware Analyst's Cookbook
Michael Hale Ligh was kind enough to provide me with a review copy of a book he recently co-authored along with Steven Adair, Blake Hartstein, and Matthew Richard, titled Malware Analyst's Cookbook and DVD: Tools and Techniques for Fighting Malicious Code. The book was an excellent read, and is an extremely valuable resource for any analyst in this industry.
First off, I am not a malware reverse engineer. Yes, I do have some experience working with malware, but not to the level that reverse engineers (RE) such as the authors tend to operate. I work with some really smart folks who do malware reverse engineering all the time, and they're very, very good at it. As such, during IR or digital forensics analysis, I tend to exchange information with the RE folks, providing what I've found and then taking what they find, and performing iterative analysis. I've found over time that this approach provides a much more in-depth analysis than the sum of it's parts.
That being said, weighing in at a hefty 18 chapters, the Cookbook covers a wide range of topics specific to reverse engineering and analyzing malware, from anonymizing your research activities to honeypots to malware classification and automated analysis and beyond. Throughout the book, the authors present "recipes" for using various tools (many of which are open-source) to solve specific problems. For example, chapter 3 includes several recipes involving YARA, an open-source, Python-based tool for identifying and classifying malware. Many other popular tools are also used, including ssdeep, Didier's PDF tools, and even RegRipper. Chapter 15 goes discusses effectively using Volatility for memory analysis. Many of the examples provided in the book are based on the real-world experiences of the authors, lending considerable credence and value to the demonstrated skills and information imparted.
Chapter 10 is near and dear to my heart, not only due to the discussion of ADSs, but also due the fact that the authors wrote their own RegRipper plugins! That's right! These guys found some things of value with RegRipper and wrote their own plugins. It brings a tear to my eye to think that my little tool is all grow'd up!
Some of the truly powerful aspects of the book include clear, thorough explanations of the presented topics, as well as easy-to-follow examples that allow the reader to follow along and learn by doing (I tend to learn more by doing than reading). Whether you're an aspiring reverse engineer, incident responder, or forensic analyst, this book will be an extremely valuable resource to you. For example, some of the explanations of how systems get infected with malware (JavaScripts, infectable document formats, HTML injection, etc.), as well as artifacts to indicate a malware infection, will prove extremely valuable to IR/DF folks. Heck, even if you're a somewhat-seasoned malware reverse engineer, it's likely that this Cookbook will show you some things that you haven't seen before, or show you some ways of looking at malware that you haven't thought of before.
Much of what's in the Cookbook goes beyond commercially available applications and clearly demonstrates the use of Python- (or Perl-) based open source tools that accomplish specific objectives. The cookbook even goes so far as to explain and demonstrate how different malware-related activities are performed, as well as how they can be detected.
I have to say that reading through the Cookbook gave me a new appreciation for what malware reverse engineers do. I also walk away from the book with a better understanding, not only of how to look for malware during IR/DF activities, but also how to better provide information and data to our reverse engineer once I've found it. I also walk away from it knowing that I'll be back. With more study and practice, I'm sure I can do some modicum of malware analysis beyond what I already do, and while I know that I'll never be at the level of the authors, I thank them for a truly exemplary and valuable resource. If I didn't already have it, this Cookbook would be on my Christmas wishlist...at the very top!
First off, I am not a malware reverse engineer. Yes, I do have some experience working with malware, but not to the level that reverse engineers (RE) such as the authors tend to operate. I work with some really smart folks who do malware reverse engineering all the time, and they're very, very good at it. As such, during IR or digital forensics analysis, I tend to exchange information with the RE folks, providing what I've found and then taking what they find, and performing iterative analysis. I've found over time that this approach provides a much more in-depth analysis than the sum of it's parts.
That being said, weighing in at a hefty 18 chapters, the Cookbook covers a wide range of topics specific to reverse engineering and analyzing malware, from anonymizing your research activities to honeypots to malware classification and automated analysis and beyond. Throughout the book, the authors present "recipes" for using various tools (many of which are open-source) to solve specific problems. For example, chapter 3 includes several recipes involving YARA, an open-source, Python-based tool for identifying and classifying malware. Many other popular tools are also used, including ssdeep, Didier's PDF tools, and even RegRipper. Chapter 15 goes discusses effectively using Volatility for memory analysis. Many of the examples provided in the book are based on the real-world experiences of the authors, lending considerable credence and value to the demonstrated skills and information imparted.
Chapter 10 is near and dear to my heart, not only due to the discussion of ADSs, but also due the fact that the authors wrote their own RegRipper plugins!
Some of the truly powerful aspects of the book include clear, thorough explanations of the presented topics, as well as easy-to-follow examples that allow the reader to follow along and learn by doing (I tend to learn more by doing than reading). Whether you're an aspiring reverse engineer, incident responder, or forensic analyst, this book will be an extremely valuable resource to you. For example, some of the explanations of how systems get infected with malware (JavaScripts, infectable document formats, HTML injection, etc.), as well as artifacts to indicate a malware infection, will prove extremely valuable to IR/DF folks. Heck, even if you're a somewhat-seasoned malware reverse engineer, it's likely that this Cookbook will show you some things that you haven't seen before, or show you some ways of looking at malware that you haven't thought of before.
Much of what's in the Cookbook goes beyond commercially available applications and clearly demonstrates the use of Python- (or Perl-) based open source tools that accomplish specific objectives. The cookbook even goes so far as to explain and demonstrate how different malware-related activities are performed, as well as how they can be detected.
I have to say that reading through the Cookbook gave me a new appreciation for what malware reverse engineers do. I also walk away from the book with a better understanding, not only of how to look for malware during IR/DF activities, but also how to better provide information and data to our reverse engineer once I've found it. I also walk away from it knowing that I'll be back. With more study and practice, I'm sure I can do some modicum of malware analysis beyond what I already do, and while I know that I'll never be at the level of the authors, I thank them for a truly exemplary and valuable resource. If I didn't already have it, this Cookbook would be on my Christmas wishlist...at the very top!
Links, Thoughts...
What's good and what's been going on lately in the world of Windows IR/DF? I think maybe things are slowing down around the holidays, as it seems that many of us who are blogging are simply sharing the same links that everyone else is blogging...kind of circular, and when you poke your head up, you realize that you've been reading the same half dozen stories for the past week.
Maybe there really isn't a whole lot going on at the moment...maybe adding something a little bit different, perhaps a different angle, will change things up just a bit.
Books
Many of you know that I've had a couple of books published, and number 5...Windows Registry Forensics...will be out shortly. WFA 2/e has been pretty successful so far, and a number of folks have sort of off-handedly asked me about a third edition. To be honest, this is something that's up to the publisher...WFA 2/e may be successful enough for a third edition, or the publisher may decide that the title and subject have run their course....who knows?
However, the question itself got me thinking along a different road...that is, what does it take to write a book? In exploring material for a third edition, I took an opportunity to ask some folks what they thought should be included in that edition, only to get some very interesting responses. Those responses then got me to thinking, "here's someone who does a lot of work...why doesn't he write a book?" I then thought, what is it that's holding folks back? There are a number of folks out there who likely have the necessary background to write a book...I mean, based on some of the books that have been written over the years, a solid background in ediscovery or digital forensic analysis should be enough to write a solid book, right?
If you're looking for a particular topic, my publisher has a page up called "Write for Syngress" for those who may be thinking about writing a book, or just tossing the idea around.
I think that a lot of folks look for someone to write a book for them, without ever thinking that maybe they could write that book themselves. Time is always a factor, but based on my experience, there are a number of decisions that need to be made, and sometimes thinking through those things can actually get you over that hump.
As such, what I'm going to be doing over time is writing a series of blog posts about writing books. I'm going to offer up my thoughts and experiences, and hope that someone out there decides to put pen to paper (figuratively, or literally) and step out and just do it. Yes, writing a book is time consuming and it can be arduous, but it can also be very rewarding.
Prefetch Files
Mark Wade recently had an article published in the DFI News regarding Prefetch file analysis. The article is a good resource for those not familiar with Prefetch files and how they might be used. I do, however, have a question about one statement made in the article:
For instance if the Standard Information Attribute (SIA) and File Name Attribute (FNA) timestamps are modified in the Master File Table (MFT) to impede analysis...
In light of what's available in Brian Carrier's File System Forensic Analysis book, I'm a bit unclear as to how FNA timestamps would be purposely modified. Does anyone have any input on that? Is anyone seeing FNA timestamps being purposely and maliciously modified in the same manner as SIA timestamps?
That question aside, I think that Mark makes a number of excellent points and observations in his article, particularly that data embedded within the Prefetch files can be used to determine a number of interesting artifacts, such as errant removable storage devices or paths, "abnormal" or deleted user accounts, etc.
Imaging Systems
Lance recently posted a "hard drive imaging process tree for basic training"; keeping in mind that it's for basic training, it's an excellent resource to look to and use.
There are a couple of things that you should consider adding if you're planning to use this decision tree for your own training purposes. For example, the first comment talks about adding chain of custody documentation...this is something that should definitely be done. Several other comments refer to collecting volatile memory...while Lance's responses are that this is covered in other modules, I tend to agree with Rob and Andrew...this is something that needs to be included at the basic level; we can no longer leave this to the advanced level.
The thing I am glad to see at the end of the entire process is "Verify Image". I can't say that it's happened too many times, but I do know of analysts who have gone on-site, acquired images, documented everything, and not verified their images. When they got back to the lab, they found that for some reason, they did not have valid images. This must be part of the process.
Great job, Lance, on producing an excellent resource! Thanks!
Oh, hey, almost forgot...thanks for updating the post to include volatile data collection!
Memory Analysis
Gl33da's got a new blog post up, this one on identifying memory images. If you do memory analysis, but don't actually perform the memory acquisition, this is an excellent post that's chock full of great information, in that she not only points out a method for determining the version of Windows of a memory image, but points out that it's already been incorporated into Volatility 1.4. Shoutz to gl33da for sharing!
If you are performing memory acquisition, are you using windd? Or are you using the MoonSols Windows Memory Toolkit Community Edition?
Addendum: Russ McRee pointed me to an article he wrote for InfoSecInstitute, titled "Security Incident Response Testing To Meet Audit Requirements". The article focuses primarily on the PCI DSS v2.0, specifically para. 12.9, which mandates the requirement for an IR capability, in addition to providing specifications. Overall, I think that the article is very good, and includes a good deal of the things I would do or recommend when writing or evaluating an IR plan.
The only real issue I have with Russ's article...and this comes from being QSA certified and on a QIRA team for far too long...is that the majority of organizations that I investigated had enough trouble just getting something down on paper, let alone a coherent IR plan. The likelihood of a comprehensive plan that was tested, and an IR team that is trained and drilled on a regular basis was slim to none. Now, this isn't all organizations obviously...this is simply based on my experience and the responses I performed.
I will say that Russ does have some very interesting information in the article that will no only benefit responders, but forensic analysts, as well as those who provided training to responders and analysts. Thanks, Russ, for pointing me to the article.
Maybe there really isn't a whole lot going on at the moment...maybe adding something a little bit different, perhaps a different angle, will change things up just a bit.
Books
Many of you know that I've had a couple of books published, and number 5...Windows Registry Forensics...will be out shortly. WFA 2/e has been pretty successful so far, and a number of folks have sort of off-handedly asked me about a third edition. To be honest, this is something that's up to the publisher...WFA 2/e may be successful enough for a third edition, or the publisher may decide that the title and subject have run their course....who knows?
However, the question itself got me thinking along a different road...that is, what does it take to write a book? In exploring material for a third edition, I took an opportunity to ask some folks what they thought should be included in that edition, only to get some very interesting responses. Those responses then got me to thinking, "here's someone who does a lot of
If you're looking for a particular topic, my publisher has a page up called "Write for Syngress" for those who may be thinking about writing a book, or just tossing the idea around.
I think that a lot of folks look for someone to write a book for them, without ever thinking that maybe they could write that book themselves. Time is always a factor, but based on my experience, there are a number of decisions that need to be made, and sometimes thinking through those things can actually get you over that hump.
As such, what I'm going to be doing over time is writing a series of blog posts about writing books. I'm going to offer up my thoughts and experiences, and hope that someone out there decides to put pen to paper (figuratively, or literally) and step out and just do it. Yes, writing a book is time consuming and it can be arduous, but it can also be very rewarding.
Prefetch Files
Mark Wade recently had an article published in the DFI News regarding Prefetch file analysis. The article is a good resource for those not familiar with Prefetch files and how they might be used. I do, however, have a question about one statement made in the article:
For instance if the Standard Information Attribute (SIA) and File Name Attribute (FNA) timestamps are modified in the Master File Table (MFT) to impede analysis...
In light of what's available in Brian Carrier's File System Forensic Analysis book, I'm a bit unclear as to how FNA timestamps would be purposely modified. Does anyone have any input on that? Is anyone seeing FNA timestamps being purposely and maliciously modified in the same manner as SIA timestamps?
That question aside, I think that Mark makes a number of excellent points and observations in his article, particularly that data embedded within the Prefetch files can be used to determine a number of interesting artifacts, such as errant removable storage devices or paths, "abnormal" or deleted user accounts, etc.
Imaging Systems
Lance recently posted a "hard drive imaging process tree for basic training"; keeping in mind that it's for basic training, it's an excellent resource to look to and use.
There are a couple of things that you should consider adding if you're planning to use this decision tree for your own training purposes. For example, the first comment talks about adding chain of custody documentation...this is something that should definitely be done. Several other comments refer to collecting volatile memory...while Lance's responses are that this is covered in other modules, I tend to agree with Rob and Andrew...this is something that needs to be included at the basic level; we can no longer leave this to the advanced level.
The thing I am glad to see at the end of the entire process is "Verify Image". I can't say that it's happened too many times, but I do know of analysts who have gone on-site, acquired images, documented everything, and not verified their images. When they got back to the lab, they found that for some reason, they did not have valid images. This must be part of the process.
Great job, Lance, on producing an excellent resource! Thanks!
Oh, hey, almost forgot...thanks for updating the post to include volatile data collection!
Memory Analysis
Gl33da's got a new blog post up, this one on identifying memory images. If you do memory analysis, but don't actually perform the memory acquisition, this is an excellent post that's chock full of great information, in that she not only points out a method for determining the version of Windows of a memory image, but points out that it's already been incorporated into Volatility 1.4. Shoutz to gl33da for sharing!
If you are performing memory acquisition, are you using windd? Or are you using the MoonSols Windows Memory Toolkit Community Edition?
Addendum: Russ McRee pointed me to an article he wrote for InfoSecInstitute, titled "Security Incident Response Testing To Meet Audit Requirements". The article focuses primarily on the PCI DSS v2.0, specifically para. 12.9, which mandates the requirement for an IR capability, in addition to providing specifications. Overall, I think that the article is very good, and includes a good deal of the things I would do or recommend when writing or evaluating an IR plan.
The only real issue I have with Russ's article...and this comes from being QSA certified and on a QIRA team for far too long...is that the majority of organizations that I investigated had enough trouble just getting something down on paper, let alone a coherent IR plan. The likelihood of a comprehensive plan that was tested, and an IR team that is trained and drilled on a regular basis was slim to none. Now, this isn't all organizations obviously...this is simply based on my experience and the responses I performed.
I will say that Russ does have some very interesting information in the article that will no only benefit responders, but forensic analysts, as well as those who provided training to responders and analysts. Thanks, Russ, for pointing me to the article.
Sunday, December 05, 2010
WFA 3/e
This fall, while I was at a couple/three conferences, I was asked if/when the third edition of WFA would be coming out. In response, I'd point out that something like this isn't really a decision for me, so much as it is a decision for the publisher.
However, that got me to thinking...as a forensic analyst, what would you like to see in a third edition of Windows Forensic Analysis?
However, that got me to thinking...as a forensic analyst, what would you like to see in a third edition of Windows Forensic Analysis?
Friday, December 03, 2010
ESENT
Corey asked a question recently in the Win4n6 Yahoo group that peaked my interest...because it had to do with a Registry key.
In short, Corey had found the entries were created under the following key:
HKLM\Software\Microsoft\ESENT\Process
First, ESENT apparently refers to the built-in JET database engine that has shipped with Windows as of Windows 2000. According to various pages at the MS site, this DB engine is very limited, not allowing remote access, and only providing for simple queries...but it is used in instances with other storage formats (flat file, Registry, etc.) are simply not suitable. According to the MS Windows SDK blog:
"The ESENT database engine can be used whenever an application wants
high-performance, low-overhead storage of structured or semi-structured data."
I then began looking into the key itself to get an idea of what was happening. I found, on my system, a number of subkeys beneath this key...ipconfig, svchost, wmplayer, etc. As I found each executable image, I opened the .exe file in PEView and saw that each .exe had an IMAGE_DEBUG_DIRECTORY, as well as a IMAGE_DEBUG_TYPE_CODEVIEW directory listed. Within the IMAGE_DEBUG_TYPE_CODEVIEW directory, I could see a reference to a .pdb, or program database file, which is where symbols and program debugging information is stored. While this is admittedly a somewhat limited and narrow view, it did occur to me that this was something to check, if you have a full image that includes the Registry hives in addition to the executable files.
Of course, both Corey and I employed ProcMon to see what was happening when an executable listed in the ESENT\Process key was run. For the monitoring I did, I opened a command prompted, typed "ipconfig /all", started my capture, and then hit "Enter" for my command in the command prompt window. As soon as the command completed, I halted monitoring in ProcMon. I then began going through the output, and found that the ipconfig.exe process itself did, in fact, query the key in question.
Corey found in his capture, for wmplayer.exe, "RegSetValue" was used on the "DEBUG\Trace Level" value; I have run the ipconfig command several times and while I did see the accesses to the "ipconfig\DEBUG\Trace Level" value (ie, RegQueryValue), I do not see any values set (via RegSetValue), nor modified.
Another interesting artifact that I saw in the ProcMon capture was that while esent.dll is not included in the PE header of the executable image file, the DLL is loaded by the ipconfig.exe process.
Okay, so this is interesting stuff...but only in a limited manner. If you Google for "ESENT\Process", you'll see a number of hits at AV sites that refer to malware. As I read through some of these (here, here), I was reminded of some of the artifacts surrounding the MUICache key, and how sometimes what is referred to as "analysis" could simply be secondary or tertiary artifacts of how the executable was run, or simply from the OS running and doing it's thing.
However, there were other links, such as this one (refers to Virut) that seemed to indicate that a closer look at the executable file itself is likely warranted. Other entries at McAfee, such as this one, further indicates that there may be malware samples for which the ESENT\Process key entries are specifically created, and that this may definitely be worth a look. In many ways, entries beneath this key may...and I say may, as more research and assistance from Microsoft is definitely needed in this area...be similar to those beneath the MUICache key, in that they are indirect artifacts created not by the executable itself, but instead by the environment or eco-system (that's just a fancy way of saying "operating system") as the malware interacts with it.
I have a couple of test images that I can look at with respect to this key, and of course, I created an esent.pl plugin (took about 5 minutes) for RegRipper to make things like testing and analysis easier.
As a side note (and shout out), I'm reading through Malware Analyst's Cookbook at the moment, and there are a LOT of really good Python and Perl recipes listed in the book that would be abundantly useful for this kind of analysis. While my own book provides a short view into what a normal PE file should look like, the Cookbook provides not only a view into what malware looks like, but it also provides tools for examining malware files up close without actually having to run them.
So, going forward...any thoughts, comments, or assistance in understanding a bit more about the ESENT\Process key would be greatly appreciated!
Addendum: For anyone who uses or has used ProcMon, or more specifically, RegMon, when running applications, you'll usually see a process accessing the "Image File Execution Options" key; when associated DLLs are loaded, you'll see similar accesses, as well, for this key. When this key is accessed, it's the operating system looking to see if there is a Debugger value associated with the specific executable image file. It is this association with debugging that led me to think...tenuous, I know...that the files with .pdb associations in their PE headers were accessing the ESENT key. My reasoning was, if the OS is going to look for some sort of debugger association once, why not twice?
In short, Corey had found the entries were created under the following key:
HKLM\Software\Microsoft\ESENT\Process
First, ESENT apparently refers to the built-in JET database engine that has shipped with Windows as of Windows 2000. According to various pages at the MS site, this DB engine is very limited, not allowing remote access, and only providing for simple queries...but it is used in instances with other storage formats (flat file, Registry, etc.) are simply not suitable. According to the MS Windows SDK blog:
"The ESENT database engine can be used whenever an application wants
high-performance, low-overhead storage of structured or semi-structured data."
I then began looking into the key itself to get an idea of what was happening. I found, on my system, a number of subkeys beneath this key...ipconfig, svchost, wmplayer, etc. As I found each executable image, I opened the .exe file in PEView and saw that each .exe had an IMAGE_DEBUG_DIRECTORY, as well as a IMAGE_DEBUG_TYPE_CODEVIEW directory listed. Within the IMAGE_DEBUG_TYPE_CODEVIEW directory, I could see a reference to a .pdb, or program database file, which is where symbols and program debugging information is stored. While this is admittedly a somewhat limited and narrow view, it did occur to me that this was something to check, if you have a full image that includes the Registry hives in addition to the executable files.
Of course, both Corey and I employed ProcMon to see what was happening when an executable listed in the ESENT\Process key was run. For the monitoring I did, I opened a command prompted, typed "ipconfig /all", started my capture, and then hit "Enter" for my command in the command prompt window. As soon as the command completed, I halted monitoring in ProcMon. I then began going through the output, and found that the ipconfig.exe process itself did, in fact, query the key in question.
Corey found in his capture, for wmplayer.exe, "RegSetValue" was used on the "DEBUG\Trace Level" value; I have run the ipconfig command several times and while I did see the accesses to the "ipconfig\DEBUG\Trace Level" value (ie, RegQueryValue), I do not see any values set (via RegSetValue), nor modified.
Another interesting artifact that I saw in the ProcMon capture was that while esent.dll is not included in the PE header of the executable image file, the DLL is loaded by the ipconfig.exe process.
Okay, so this is interesting stuff...but only in a limited manner. If you Google for "ESENT\Process", you'll see a number of hits at AV sites that refer to malware. As I read through some of these (here, here), I was reminded of some of the artifacts surrounding the MUICache key, and how sometimes what is referred to as "analysis" could simply be secondary or tertiary artifacts of how the executable was run, or simply from the OS running and doing it's thing.
However, there were other links, such as this one (refers to Virut) that seemed to indicate that a closer look at the executable file itself is likely warranted. Other entries at McAfee, such as this one, further indicates that there may be malware samples for which the ESENT\Process key entries are specifically created, and that this may definitely be worth a look. In many ways, entries beneath this key may...and I say may, as more research and assistance from Microsoft is definitely needed in this area...be similar to those beneath the MUICache key, in that they are indirect artifacts created not by the executable itself, but instead by the environment or eco-system (that's just a fancy way of saying "operating system") as the malware interacts with it.
I have a couple of test images that I can look at with respect to this key, and of course, I created an esent.pl plugin (took about 5 minutes) for RegRipper to make things like testing and analysis easier.
As a side note (and shout out), I'm reading through Malware Analyst's Cookbook at the moment, and there are a LOT of really good Python and Perl recipes listed in the book that would be abundantly useful for this kind of analysis. While my own book provides a short view into what a normal PE file should look like, the Cookbook provides not only a view into what malware looks like, but it also provides tools for examining malware files up close without actually having to run them.
So, going forward...any thoughts, comments, or assistance in understanding a bit more about the ESENT\Process key would be greatly appreciated!
Addendum: For anyone who uses or has used ProcMon, or more specifically, RegMon, when running applications, you'll usually see a process accessing the "Image File Execution Options" key; when associated DLLs are loaded, you'll see similar accesses, as well, for this key. When this key is accessed, it's the operating system looking to see if there is a Debugger value associated with the specific executable image file. It is this association with debugging that led me to think...tenuous, I know...that the files with .pdb associations in their PE headers were accessing the ESENT key. My reasoning was, if the OS is going to look for some sort of debugger association once, why not twice?
Wednesday, December 01, 2010
A Bit More About Timelines...
Just a few more thoughts about timelines and data reduction...
One of the comments to my previous post brought up the fact that sometimes, you DO want everything you can get into a timeline. The example given was a murder investigation...in such cases, you may want to "see" what an individual's online or "cyber" life looked like for the last few days or weeks. In such instances, I completely agree that a comprehensive timeline could be very valuable, but in such instances, a comprehensive timeline would be an actual goal of your exam, wouldn't it? Everything goes back to the goals of the examination.
There are other things you can do with respect to data reduction and timelines. One of the tools I use to transition the events file (file containing the listing of all events) into a timeline includes an option to restrict the time window that I want to look at:
C:\tools>parse.pl -f D:\cases\events.txt -r 11/20/2010-11/22/2010 > D:\cases\tln.txt
This command line tells parse.pl to create a timeline using all events from 00:00:00 Z on 11/20 to 23:59:59 Z on 11/22.
Another tool you can use against the events file is grep. The "-v" option is for inverting regex matches, and allows you to remove all lines that meet a specific criteria...such as application updates, Restore Point creation/deletion, etc. This can be very useful and powerful in removing noise from your timeline.
Rob Lee also pointed out that dumping all of the Registry key LastWrite times into a timeline has been valuable, and in at least one instance, revealed a very interesting artifact. With the tools and methodology I use, I've created mini-timelines of the various verbose data sources...Registry hives generally have a LOT of keys, and I may not want to include everything, so I can instead go find the interesting tidbits and add only those items, documenting my decision to include or exclude certain data. I've also done this with web server logs during SQL injection exams, and even used this approach to answer very specific questions that did not require that entire timelines be created; a micro-timeline of just the event ID 528, type 10 events from the Security Event Log provided the answer I needed.
One final point on data reduction in your timelines...as with creating timelines, run your data reduction from an educated, knowledgeable standpoint. If you can't justify the data reduction steps in your own documentation, don't do it. Not only is repeatability something we're striving for, but being able to come back to the exam 6 months or more down the road, and understand what you did...I think everyone sees the value in that.
One of the comments to my previous post brought up the fact that sometimes, you DO want everything you can get into a timeline. The example given was a murder investigation...in such cases, you may want to "see" what an individual's online or "cyber" life looked like for the last few days or weeks. In such instances, I completely agree that a comprehensive timeline could be very valuable, but in such instances, a comprehensive timeline would be an actual goal of your exam, wouldn't it? Everything goes back to the goals of the examination.
There are other things you can do with respect to data reduction and timelines. One of the tools I use to transition the events file (file containing the listing of all events) into a timeline includes an option to restrict the time window that I want to look at:
C:\tools>parse.pl -f D:\cases\events.txt -r 11/20/2010-11/22/2010 > D:\cases\tln.txt
This command line tells parse.pl to create a timeline using all events from 00:00:00 Z on 11/20 to 23:59:59 Z on 11/22.
Another tool you can use against the events file is grep. The "-v" option is for inverting regex matches, and allows you to remove all lines that meet a specific criteria...such as application updates, Restore Point creation/deletion, etc. This can be very useful and powerful in removing noise from your timeline.
Rob Lee also pointed out that dumping all of the Registry key LastWrite times into a timeline has been valuable, and in at least one instance, revealed a very interesting artifact. With the tools and methodology I use, I've created mini-timelines of the various verbose data sources...Registry hives generally have a LOT of keys, and I may not want to include everything, so I can instead go find the interesting tidbits and add only those items, documenting my decision to include or exclude certain data. I've also done this with web server logs during SQL injection exams, and even used this approach to answer very specific questions that did not require that entire timelines be created; a micro-timeline of just the event ID 528, type 10 events from the Security Event Log provided the answer I needed.
One final point on data reduction in your timelines...as with creating timelines, run your data reduction from an educated, knowledgeable standpoint. If you can't justify the data reduction steps in your own documentation, don't do it. Not only is repeatability something we're striving for, but being able to come back to the exam 6 months or more down the road, and understand what you did...I think everyone sees the value in that.
Sunday, November 28, 2010
Stuff
Timelines
Corey Harrell recently posted to his blog about using Calc (the spreadsheet program associated with OpenOffice) to perform timeline analysis. Corey's post was very revealing and thorough, and clearly demonstrates to the reader that here's a guy who does timeline analysis. I mean, Corey looks at regular expressions for searching, etc., and really does a good job of covering a lot of the different analysis aspects that you'd do in Excel, and provides a good indication that he's actually been doing this kind of analysis. Great job, Corey.
However, there are two things that came up in the post that might be good points for discussion. First, Corey says that his exploration originated from an anonymous question asking if Calc could be used in place of Excel. I applaud Corey's efforst, but this question demonstrates how some analysts will continue in asking these kinds of questions, rather than doing their own research and posting the results. This is one of those things that could have been easily stated as "Calc can also be used...", rather than as an anonymous question.
The other issue is the concern that Corey expressed with respect to the spreadsheet program's ability to handle massive numbers (100K or more) of rows. This is definitely a concern (particularly with versions of Excel that were pre-Office 2007), but it also demonstrates how timelines, which are meant to some degree to be a data reduction technique, can actually become very cumbersome and even slow the analyst down, simply by the shear volume of data. Yes, extracting data and generating a timeline is less data than a full image (i.e., a directory listing of a 160GB hard drive is much less than 160GB...), but it appears that so much data is capable of being added to a timeline that doing so could easily overwhelm an analyst.
Timelines and Data Reduction
One solution to this that I highly recommend is an educated, knowledgeable approach to timeline development and analysis, which is something Chris points to in his Sniper Forensics presentation. Rather than throwing everything (even the kitchen sink, if it has a time stamp) into your timeline and sorting it out from there, why not instead start with the goals of your examination, what you're trying to show, and go on from there? Your goals will show you what you need to look at, and what you need to show.
After all, one of the benefits and goals of timelines is...and should be...data reduction. While a timeline compiled from an abundance of data sources is indeed a reduction of data volume, is it really a reduction of data to be analyzed? In many cases, it may not be.
Consider this...let's say that while driving your car, you hear an odd noise, maybe a squeal of some kind, coming from front left tire every time you break. What do you do? Do you disassemble the entire car in hopes of finding something bad, or something that might be responsible for the noise? Or do you do some testing to ensure that the noise is really coming from where you think it is, and under what specific conditions?
No, I'm not saying that we throw everything out and start over. Rather, what I'm suggesting is that rather than throwing everything into a timeline, assess the relative value of the data prior to adding it. One excellent example of this is a SQL injection analysis I did...I started with the file system metadata, and added just the web server logs that contained the pertinent SQL injection statements. There was no need to add Event Log data, nor all of the LastWrite times from all of the Registry keys from the hive files on the system. There was simply no value in doing this; in fact, doing so would have complicated the analysis, simply through shear volume. Is this an extreme example? No, I don't think that it is.
By reducing the data that we need to analyze, even if doing so in through the analysis (determine what we can remove from timeline as "noise", etc.), we then get to a point where relational analysis...that is, analyzing different systems in relation to each other, we can get a better view of what may have occurred (and when) in multi-system incidents/breaches. Remember, in the five field timeline format that I've recommended using, there is a field for the system name, as well as one for the user name. Using these fields, you can observe the use of domain credentials across multiple systems, for example.
Goals
I know that many folks are going to say, "What if you don't know what you're looking for?", and the answer to that is, "If you don't know what you're looking for, why are you doing analysis?" Seriously. If you don't know what the goals of your analysis are, why are you doing it?
Sometimes folks will say, "my goals are to find all bad stuff". Well...what constitutes "bad"? What if you find nmap and Metasploit installed on a system? Is it bad? What if the user is a network engineer tasked with vulnerability scanning and assessment? Then, is this find "bad"?
From the questions I receive, a lot of times I think that there is difficulty in defining goals. Does anyone really want to "find all malware"? Really? So you want to know about every BHO and bit of spyware? Given some home user systems, imagine how long it would take to locate, document, and categorize all malware on a system. Usually what I have found is that "find all malware" really means "find the malware that may have been associated with a particular incident or event". Then, getting the person you're working with to describe the event can help you narrow down the goals of your analysis. After all, they're talking to you for a reason, right? If they could do the analysis themselves, there would be no reason to talk to you. Developing a concise set of goals allows you to define and set expectations, as well as deliver something tangible and useful.
Timeline as a Tool
Timeline analysis is an extremely useful and valuable tool...but like any other tool, it's just a tool. The actual analysis is up to the analyst. There may be times when it simply doesn't make sense to create a timeline...if that's the case, then don't bother. However, if it does make sense to develop a timeline, then do so intelligently.
Volatility Updates
Gleeda recently tweeted about documentation for Volatility being available. If you do any memory forensics, this is an excellent resource that walks you through getting all set up and running with the full capabilities of Volatility.
Corey Harrell recently posted to his blog about using Calc (the spreadsheet program associated with OpenOffice) to perform timeline analysis. Corey's post was very revealing and thorough, and clearly demonstrates to the reader that here's a guy who does timeline analysis. I mean, Corey looks at regular expressions for searching, etc., and really does a good job of covering a lot of the different analysis aspects that you'd do in Excel, and provides a good indication that he's actually been doing this kind of analysis. Great job, Corey.
However, there are two things that came up in the post that might be good points for discussion. First, Corey says that his exploration originated from an anonymous question asking if Calc could be used in place of Excel. I applaud Corey's efforst, but this question demonstrates how some analysts will continue in asking these kinds of questions, rather than doing their own research and posting the results. This is one of those things that could have been easily stated as "Calc can also be used...", rather than as an anonymous question.
The other issue is the concern that Corey expressed with respect to the spreadsheet program's ability to handle massive numbers (100K or more) of rows. This is definitely a concern (particularly with versions of Excel that were pre-Office 2007), but it also demonstrates how timelines, which are meant to some degree to be a data reduction technique, can actually become very cumbersome and even slow the analyst down, simply by the shear volume of data. Yes, extracting data and generating a timeline is less data than a full image (i.e., a directory listing of a 160GB hard drive is much less than 160GB...), but it appears that so much data is capable of being added to a timeline that doing so could easily overwhelm an analyst.
Timelines and Data Reduction
One solution to this that I highly recommend is an educated, knowledgeable approach to timeline development and analysis, which is something Chris points to in his Sniper Forensics presentation. Rather than throwing everything (even the kitchen sink, if it has a time stamp) into your timeline and sorting it out from there, why not instead start with the goals of your examination, what you're trying to show, and go on from there? Your goals will show you what you need to look at, and what you need to show.
After all, one of the benefits and goals of timelines is...and should be...data reduction. While a timeline compiled from an abundance of data sources is indeed a reduction of data volume, is it really a reduction of data to be analyzed? In many cases, it may not be.
Consider this...let's say that while driving your car, you hear an odd noise, maybe a squeal of some kind, coming from front left tire every time you break. What do you do? Do you disassemble the entire car in hopes of finding something bad, or something that might be responsible for the noise? Or do you do some testing to ensure that the noise is really coming from where you think it is, and under what specific conditions?
No, I'm not saying that we throw everything out and start over. Rather, what I'm suggesting is that rather than throwing everything into a timeline, assess the relative value of the data prior to adding it. One excellent example of this is a SQL injection analysis I did...I started with the file system metadata, and added just the web server logs that contained the pertinent SQL injection statements. There was no need to add Event Log data, nor all of the LastWrite times from all of the Registry keys from the hive files on the system. There was simply no value in doing this; in fact, doing so would have complicated the analysis, simply through shear volume. Is this an extreme example? No, I don't think that it is.
By reducing the data that we need to analyze, even if doing so in through the analysis (determine what we can remove from timeline as "noise", etc.), we then get to a point where relational analysis...that is, analyzing different systems in relation to each other, we can get a better view of what may have occurred (and when) in multi-system incidents/breaches. Remember, in the five field timeline format that I've recommended using, there is a field for the system name, as well as one for the user name. Using these fields, you can observe the use of domain credentials across multiple systems, for example.
Goals
I know that many folks are going to say, "What if you don't know what you're looking for?", and the answer to that is, "If you don't know what you're looking for, why are you doing analysis?" Seriously. If you don't know what the goals of your analysis are, why are you doing it?
Sometimes folks will say, "my goals are to find all bad stuff". Well...what constitutes "bad"? What if you find nmap and Metasploit installed on a system? Is it bad? What if the user is a network engineer tasked with vulnerability scanning and assessment? Then, is this find "bad"?
From the questions I receive, a lot of times I think that there is difficulty in defining goals. Does anyone really want to "find all malware"? Really? So you want to know about every BHO and bit of spyware? Given some home user systems, imagine how long it would take to locate, document, and categorize all malware on a system. Usually what I have found is that "find all malware" really means "find the malware that may have been associated with a particular incident or event". Then, getting the person you're working with to describe the event can help you narrow down the goals of your analysis. After all, they're talking to you for a reason, right? If they could do the analysis themselves, there would be no reason to talk to you. Developing a concise set of goals allows you to define and set expectations, as well as deliver something tangible and useful.
Timeline as a Tool
Timeline analysis is an extremely useful and valuable tool...but like any other tool, it's just a tool. The actual analysis is up to the analyst. There may be times when it simply doesn't make sense to create a timeline...if that's the case, then don't bother. However, if it does make sense to develop a timeline, then do so intelligently.
Volatility Updates
Gleeda recently tweeted about documentation for Volatility being available. If you do any memory forensics, this is an excellent resource that walks you through getting all set up and running with the full capabilities of Volatility.
Monday, November 22, 2010
More Updates
New Blog
Ken Pryor has started a new blog, and has his first post up as of Sun, 21 Nov. Check it out, and add it to your RSS feed. I'm sure Ken's going to have some gems.
I met Ken face-to-face at the WACCI conference a bit ago. He's a great guy, very knowledgeable, and very enthusiastic. Speaking of which, Ken was at the WACCI conference along with Brad Garnett, who's also posted to his blog recently. If you like some caffeine-induced forensic ramblings, stop on by and take a look.
Confessor
Russ reached to me recently to let me know about Confessor, a tool that he'd covered in a recent toolsmith column. Russ had previously mentioned MIR-ROR, and says that Confessor uses similar tools but deploys them in an "enterprise-capable manner". Also from Russ's description of Confessor and another tool (mentioned below):
"These tools were born of needing better utilities for incident response and security analysis in complex, massive cloud-like environments."
Russ also mentioned MOLE in his toolsmith article; "MOLE" stands for "malicious online link engine", which allows the analyst to validate URLs to see if malware was present. I can see how a tool like this would be very useful for analysts during a malware investigations and incident response.
Questions
I received a question the other day that I thought was interesting, because I'd seen it before. Back when I had submitted my proposal for the Windows Registry Forensics book, all of the proposal reviewers had stated that this book would need to compare and contrast RegRipper to the commercially available Registry "analysis" tools.
As it turned out, I wasn't able to do this for the book...for the simple reason that I didn't have access to those commercial tools. I don't use EnCase at work, nor do I use FTK. I did try to get a temporary license for one of the commercial tools, and was told "no". In the spirit of full disclosure, I did have an opportunity to meet Brian Karney of AccessData, and he did offer to discuss providing a temporary license for the AccessData product, but by then I was so close to the deadline for the book that there simply wasn't time to go back and work this into the book. I did reference Technology Pathways ProDiscover in the book, and that's because I had access to that commercial tool.
Also, I used quotes around the word "analysis" earlier, because most commercial tools are simply viewers...it's up to the analyst to perform analysis. To some extent, RegRipper is also a viewer, of sorts, although it doesn't so much leave the "what's important" up to the analyst, but instead allows the analyst to extract and analyze what is likely the more important and valuable data.
The question I received was right along the same lines. I guess on the surface, questions such as "how is RegRipper better than or different from the commercial tools" is one that comes from folks who, for the most part, haven't really used RegRipper much if at all, and have pretty much haven't really used the commercial tools to a great extent. I would also think that the question also comes from not really having conducted a great deal of Registry analysis. I wouldn't say that RegRipper is any better than any other tool...because it's just a tool, and is therefore only as useful or as good as the analyst using it. Like any tool that's used improperly, RegRipper would be seen as useless. Or, a knowledgeable analyst can use the tool effectively and even find new ways to use it that had not been thought of before, particularly by the designer.
One of the benefits and useful features of RegRipper is that it's open source, and the tool can be modified to suit your needs. Chris Perkins has modified RegRipper, and so did Adam James. Okay, so most folks are likely to say to this, "...but I don't program", and may even qualify that with "...in Perl." That's okay, because you can always ask someone to assist in meeting your needs. One of the reasons many folks provide tools for free is to get feedback from others who are either doing the same or similar work, or those who may be new to field and have a fresh view or perspective. So when I'm at a conference, and talk to someone who says, "...but I can't program...", I will generally ask them if they have email...because if they do, they can ask someone for assistance.
Another benefit of RegRipper as an open source tool is that if you need something done with a plugin...a new plugin written, or a current plugin with something a bit different done with the output...it's a simple matter to change things. Early on, shortly after releasing RegRipper, I received a request or two for XML output...in response, I asked for recommendations on a style sheet...and never heard back. I've received requests for .csv output...but it's a simple matter for someone to open the plugins of their choice in Notepad, commenting out (add "#" to the beginning of the line) the appropriate "::rptMsg()" statement, and adding their own. Or copy a plugin to a different name...say, copy uassist.pl to uassist_csv.pl and make the appropriate changes.
Okay, so what's the point of all this? To answer the original question, RegRipper is open source, so if you want to know how something is done or if you want to change something, just open up the appropriate file in Notepad. If you're not a programmer, ask someone. It's that easy. RegRipper isn't any better than any other tool, simply because it's not the tool, but the analyst that plays the most important role in any examination.
ZeroAccess Write-up
I was reading through Giuseppe Bonfa's write-up of the ZeroAccess/Max++ rootkit recently, and I have to say...I was interested not only in how detailed and thorough the write-up was, but also the steps taken by the malware author.
In part 1 of the reverse engineering write-up, Giuseppe points out an important artifact associated with this malware...a randomly named Windows service. According the write-up, the service is installed as a kernel driver, set to load on demand, and the ImagePath is set to "\*". The Service key name itself begins with a '.' (dot).
In part 2, Giuseppe reverse engineer's the kernel-mode device driver. His analysis revealed that when the kernel-mode driver loads, it first deletes it's Services Registry key, and then the entries under the "Enum\Root\LEGACY_" path. Apparently, the author(s) of this malware are taking steps to protect their gem from discovery, and are doing so from learning from incident responders and forensic analysts.
Giuseppe's write-up is as thorough as it is interesting. Take an opportunity to read through it...it's not only a good example for reverse engineers, but it's also good for other analysts to see so that they can understand the perspective of a reverse engineer, as well as what a reverse engineer can come up with and find out about malware. In this case, we've not only seen a rootkit that creates a hidden volume for its files, but also actively takes steps to obfuscate its presence on a live system.
OffensiveComputing also has a bit about the reverse engineering of this crimeware rootkit.
Ken Pryor has started a new blog, and has his first post up as of Sun, 21 Nov. Check it out, and add it to your RSS feed. I'm sure Ken's going to have some gems.
I met Ken face-to-face at the WACCI conference a bit ago. He's a great guy, very knowledgeable, and very enthusiastic. Speaking of which, Ken was at the WACCI conference along with Brad Garnett, who's also posted to his blog recently. If you like some caffeine-induced forensic ramblings, stop on by and take a look.
Confessor
Russ reached to me recently to let me know about Confessor, a tool that he'd covered in a recent toolsmith column. Russ had previously mentioned MIR-ROR, and says that Confessor uses similar tools but deploys them in an "enterprise-capable manner". Also from Russ's description of Confessor and another tool (mentioned below):
"These tools were born of needing better utilities for incident response and security analysis in complex, massive cloud-like environments."
Russ also mentioned MOLE in his toolsmith article; "MOLE" stands for "malicious online link engine", which allows the analyst to validate URLs to see if malware was present. I can see how a tool like this would be very useful for analysts during a malware investigations and incident response.
Questions
I received a question the other day that I thought was interesting, because I'd seen it before. Back when I had submitted my proposal for the Windows Registry Forensics book, all of the proposal reviewers had stated that this book would need to compare and contrast RegRipper to the commercially available Registry "analysis" tools.
As it turned out, I wasn't able to do this for the book...for the simple reason that I didn't have access to those commercial tools. I don't use EnCase at work, nor do I use FTK. I did try to get a temporary license for one of the commercial tools, and was told "no". In the spirit of full disclosure, I did have an opportunity to meet Brian Karney of AccessData, and he did offer to discuss providing a temporary license for the AccessData product, but by then I was so close to the deadline for the book that there simply wasn't time to go back and work this into the book. I did reference Technology Pathways ProDiscover in the book, and that's because I had access to that commercial tool.
Also, I used quotes around the word "analysis" earlier, because most commercial tools are simply viewers...it's up to the analyst to perform analysis. To some extent, RegRipper is also a viewer, of sorts, although it doesn't so much leave the "what's important" up to the analyst, but instead allows the analyst to extract and analyze what is likely the more important and valuable data.
The question I received was right along the same lines. I guess on the surface, questions such as "how is RegRipper better than or different from the commercial tools" is one that comes from folks who, for the most part, haven't really used RegRipper much if at all, and have pretty much haven't really used the commercial tools to a great extent. I would also think that the question also comes from not really having conducted a great deal of Registry analysis. I wouldn't say that RegRipper is any better than any other tool...because it's just a tool, and is therefore only as useful or as good as the analyst using it. Like any tool that's used improperly, RegRipper would be seen as useless. Or, a knowledgeable analyst can use the tool effectively and even find new ways to use it that had not been thought of before, particularly by the designer.
One of the benefits and useful features of RegRipper is that it's open source, and the tool can be modified to suit your needs. Chris Perkins has modified RegRipper, and so did Adam James. Okay, so most folks are likely to say to this, "...but I don't program", and may even qualify that with "...in Perl." That's okay, because you can always ask someone to assist in meeting your needs. One of the reasons many folks provide tools for free is to get feedback from others who are either doing the same or similar work, or those who may be new to field and have a fresh view or perspective. So when I'm at a conference, and talk to someone who says, "...but I can't program...", I will generally ask them if they have email...because if they do, they can ask someone for assistance.
Another benefit of RegRipper as an open source tool is that if you need something done with a plugin...a new plugin written, or a current plugin with something a bit different done with the output...it's a simple matter to change things. Early on, shortly after releasing RegRipper, I received a request or two for XML output...in response, I asked for recommendations on a style sheet...and never heard back. I've received requests for .csv output...but it's a simple matter for someone to open the plugins of their choice in Notepad, commenting out (add "#" to the beginning of the line) the appropriate "::rptMsg()" statement, and adding their own. Or copy a plugin to a different name...say, copy uassist.pl to uassist_csv.pl and make the appropriate changes.
Okay, so what's the point of all this? To answer the original question, RegRipper is open source, so if you want to know how something is done or if you want to change something, just open up the appropriate file in Notepad. If you're not a programmer, ask someone. It's that easy. RegRipper isn't any better than any other tool, simply because it's not the tool, but the analyst that plays the most important role in any examination.
ZeroAccess Write-up
I was reading through Giuseppe Bonfa's write-up of the ZeroAccess/Max++ rootkit recently, and I have to say...I was interested not only in how detailed and thorough the write-up was, but also the steps taken by the malware author.
In part 1 of the reverse engineering write-up, Giuseppe points out an important artifact associated with this malware...a randomly named Windows service. According the write-up, the service is installed as a kernel driver, set to load on demand, and the ImagePath is set to "\*". The Service key name itself begins with a '.' (dot).
In part 2, Giuseppe reverse engineer's the kernel-mode device driver. His analysis revealed that when the kernel-mode driver loads, it first deletes it's Services Registry key, and then the entries under the "Enum\Root\LEGACY_
Giuseppe's write-up is as thorough as it is interesting. Take an opportunity to read through it...it's not only a good example for reverse engineers, but it's also good for other analysts to see so that they can understand the perspective of a reverse engineer, as well as what a reverse engineer can come up with and find out about malware. In this case, we've not only seen a rootkit that creates a hidden volume for its files, but also actively takes steps to obfuscate its presence on a live system.
OffensiveComputing also has a bit about the reverse engineering of this crimeware rootkit.
Wednesday, November 17, 2010
Updates
CyberSpeak, 8 Nov
Be sure to check out the CyberSpeak 8 Nov podcast, with an interview of Kristinn, creator of Log2Timeline. There's some Lubie, some iPhone stuff, and lots of Ovie! Good stuff, Ovie, thanks for putting these podcasts together and entertaining us all.
Windows 7 & USB Devices
A member of the Win4n6 group recently posted that there seems to be yet another place that Windows 7 tracks USB removable storage devices. The key path is:
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\EMDMgmt
This key appears to have to do with ReadyBoost, and applies to Vista, as well as Windows 7, systems. The key names for each of the devices listed contains information similar to what's in the DeviceClasses key, including the serial number (bold in the below example) for the device, as illustrated below:
\_??_USBSTOR#Disk&Ven_Best_Buy&Prod_Geek_Squad_U3&Rev_6.15#0C90195032E36889&0#{53f56307-b6bf-11d0-94f2-00a0c91efb8b}GEEKSQUAD_1414378827
The values beneath each key include things such as the physical size of the device, as well the date that it was last tested (presumably by ReadyBoost for use as a RAM cache). I have a Windows 7 system for testing, as well as set of hive files from a Vista system, and I see entries for devices that include thumb drives and even an iPod, but not for a digital camera that had been connected to the system.
This might be a very good resource, as I've seen where some folks have asked for the physical size information of a USB device. It would be interesting to see if external HDD enclosures appear in this key, as well, and under what conditions the key LastWrite time is updated.
Resources
CodeProject
F-Response
There's a new post over on the NewInForensics blog that talks about using F-Response, in this case when analyzing Windows Event Logs (.evtx) files. I have to say that I'm glad to see others using this tool, and running tests like this, as it tells me two things. One is that folks are deciding to pick up tools and run their own tests.
The other is that folks in the community and industry are beginning to really realize and acknowledge how useful and truly powerful a tool F-Response really is, and they're using it as such.
When it comes to Windows Event Logs (.evtx) from Vista and above systems, I like to use LogParser from MS to parse the logs into some text-based format, and then use Perl to put the entries in a TLN format for inclusion into a timeline, or for generating mini-timelines. Sometimes I get questions that are best answered by creating mini-timelines (sort of the opposite of super timelines) from just RDP login events, W32Time events, etc.
OpenSource Tools
Brian mentioned recently that there's a new site available called OpenSourceForensics. From Brian:
One of the take aways from the Sleuth Kit and Open Source Digital Forensics Conference last year was that the community needed a site where examiners could go to find tools and learn about which ones were better than others.
This is a great resource, as one of the issues I hear from folks is that tools are out there, but they're OUT there...there's no single resource or location where an examiner can go to search for or find a tool, or get input from other analysts on the usefulness of the tool. Hopefully, with input from examiners and analysts, this can become an exemplary resource...but remember, folks, it takes effort from everyone!
Add to that a big thanks and shout-out to Brian for this, as well as for the Open Source Conference last June...Brian also mentioned that there will be another one next June!
Note
I presented at the PFIC2010 conference recently, and while I was there, someone came up and told me that they had all of my books. I was going to say something witty, and ask which one they liked best or opened the most, only to have them start off by saying, "...File System Forensic Analysis..."...uh...that's Brian, not me. Brian has hair, and is much smarter than I.
SecTor.ca
Speaking of conferences, SecTor videos are available. I watched Greg Hoglund's keynote presentation, and correlated to what I heard there about the APT and focused attacks to what I saw in Dave Nardoni's presentation at PFIC2010.
During the keynote, Greg pimped Windows Forensic Analysis 2/e during his presentation...very cool, Greg, thanks!
Greg went on to say that the perimeter is disappearing through the use of mobile devices, and that host systems are becoming more important than ever. Early in his keynote, he talked about threat intelligence achieved through host-based analysis, and how many folks have a simple, flash-and-go response policy...wipe the drive of a potentially infected system, re-install, and move on. I think that one of the scariest things...well, should be one of the scariest things...is that Greg pointed out that there's an economy behind gaining access to host systems. That's right...people are paying money to gain access to your systems!
Finally, during his presentation, Greg mentioned a couple of times how MD5 hashes are just short of useless for analysis of well-thought-out intrusions. I know someone who'd be upset about that, if they bothered to watch videos like this.
Be sure to check out the CyberSpeak 8 Nov podcast, with an interview of Kristinn, creator of Log2Timeline. There's some Lubie, some iPhone stuff, and lots of Ovie! Good stuff, Ovie, thanks for putting these podcasts together and entertaining us all.
Windows 7 & USB Devices
A member of the Win4n6 group recently posted that there seems to be yet another place that Windows 7 tracks USB removable storage devices. The key path is:
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\EMDMgmt
This key appears to have to do with ReadyBoost, and applies to Vista, as well as Windows 7, systems. The key names for each of the devices listed contains information similar to what's in the DeviceClasses key, including the serial number (bold in the below example) for the device, as illustrated below:
\_??_USBSTOR#Disk&Ven_Best_Buy&Prod_Geek_Squad_U3&Rev_6.15#0C90195032E36889&0#{53f56307-b6bf-11d0-94f2-00a0c91efb8b}GEEKSQUAD_1414378827
The values beneath each key include things such as the physical size of the device, as well the date that it was last tested (presumably by ReadyBoost for use as a RAM cache). I have a Windows 7 system for testing, as well as set of hive files from a Vista system, and I see entries for devices that include thumb drives and even an iPod, but not for a digital camera that had been connected to the system.
This might be a very good resource, as I've seen where some folks have asked for the physical size information of a USB device. It would be interesting to see if external HDD enclosures appear in this key, as well, and under what conditions the key LastWrite time is updated.
Resources
CodeProject
F-Response
There's a new post over on the NewInForensics blog that talks about using F-Response, in this case when analyzing Windows Event Logs (.evtx) files. I have to say that I'm glad to see others using this tool, and running tests like this, as it tells me two things. One is that folks are deciding to pick up tools and run their own tests.
The other is that folks in the community and industry are beginning to really realize and acknowledge how useful and truly powerful a tool F-Response really is, and they're using it as such.
When it comes to Windows Event Logs (.evtx) from Vista and above systems, I like to use LogParser from MS to parse the logs into some text-based format, and then use Perl to put the entries in a TLN format for inclusion into a timeline, or for generating mini-timelines. Sometimes I get questions that are best answered by creating mini-timelines (sort of the opposite of super timelines) from just RDP login events, W32Time events, etc.
OpenSource Tools
Brian mentioned recently that there's a new site available called OpenSourceForensics. From Brian:
One of the take aways from the Sleuth Kit and Open Source Digital Forensics Conference last year was that the community needed a site where examiners could go to find tools and learn about which ones were better than others.
This is a great resource, as one of the issues I hear from folks is that tools are out there, but they're OUT there...there's no single resource or location where an examiner can go to search for or find a tool, or get input from other analysts on the usefulness of the tool. Hopefully, with input from examiners and analysts, this can become an exemplary resource...but remember, folks, it takes effort from everyone!
Add to that a big thanks and shout-out to Brian for this, as well as for the Open Source Conference last June...Brian also mentioned that there will be another one next June!
Note
I presented at the PFIC2010 conference recently, and while I was there, someone came up and told me that they had all of my books. I was going to say something witty, and ask which one they liked best or opened the most, only to have them start off by saying, "...File System Forensic Analysis..."...uh...that's Brian, not me. Brian has hair, and is much smarter than I.
SecTor.ca
Speaking of conferences, SecTor videos are available. I watched Greg Hoglund's keynote presentation, and correlated to what I heard there about the APT and focused attacks to what I saw in Dave Nardoni's presentation at PFIC2010.
During the keynote, Greg pimped Windows Forensic Analysis 2/e during his presentation...very cool, Greg, thanks!
Greg went on to say that the perimeter is disappearing through the use of mobile devices, and that host systems are becoming more important than ever. Early in his keynote, he talked about threat intelligence achieved through host-based analysis, and how many folks have a simple, flash-and-go response policy...wipe the drive of a potentially infected system, re-install, and move on. I think that one of the scariest things...well, should be one of the scariest things...is that Greg pointed out that there's an economy behind gaining access to host systems. That's right...people are paying money to gain access to your systems!
Finally, during his presentation, Greg mentioned a couple of times how MD5 hashes are just short of useless for analysis of well-thought-out intrusions. I know someone who'd be upset about that, if they bothered to watch videos like this.
Wednesday, November 03, 2010
Randomness
Writing Books...and whatnot...
As I've mentioned, Windows Registry Forensics is nearing completion (I'm reviewing the proofs now...) and according to Syngress, will be available in January. When something like this is coming out, as with WFA 2/e, the biggest question I tend to get is, "Did you cover the differences/changes in Windows versions?"
Most times, I'm taken aback by this question. I was at the CSI 2010 conference recently, and went by the Syngress table. I talked to someone who was looking at a copy of WFA 2/e, and once he realized that I was the author, he asked me that question. In order to get a better idea how to answer that question, I turned it around and asked him, "...like what?" To that, I got a blank stare in response.
I think...and please, correct me if I'm wrong here...but the real, underlying question is, what are the new sources and locations of potentially valuable data?
In many ways, this is something of a loaded question...because, yes, there are some things that are different between versions of Windows, and in particular between the venerable Windows XP and the shiny new Windows 7. But I could sit here for the better part of the day talking about the differences and never, not once, hit on anything of value to you or to your examinations. Some file paths and Registry locations have changed...while some haven't. Some file formats have changed, while new ones have been added. Some of the new file types in Windows 7...for example, sticky notes...are a bit questionable when it comes to their potential value as evidence.
My suggestion to the community is that if you want to see this kind of thing, start talking. What good does it do to stand there asking "...did you cover all of the changes?" AFTER the book has been written and published, and you're holding it in your hands (with your thumb on the table of contents)? Seriously. If you've got a concern, ask someone. I think you'll be surprised...if nothing else, that you're not the only person with that question. Sometimes, that's all it takes...
Registry Analysis
Speaking of working on the book (the proofs, really), one of the things that really intrigues me about Registry analysis is...well...Registry analysis.
One of the most valuable uses for Registry analysis that I've found is that you can go into the Registry and see historical access to a range of resources...USB removable storage devices (thumb drives, digital cameras, etc.), network shares, remote systems (via RDP or VNC), files that no longer exist on the system, etc. In many cases, you can tie a good deal of this activity to a user, as well as to a specific time frame. You can see what a user searched for on the system.
I've performed examinations of systems where there was a question regarding digital images...we'll just leave it at that (most of us know where I'm going with this...). Someone had claimed that the images had been put on the system by malware, and yet the Registry clearly showed not only access to the files in question, but also showed an association with a specific viewing application, and time stamps indicating when the files had been accessed. These time stamps from the Registry corresponded to file system metadata, as well as metadata from Prefetch files associated with the viewing application(s) (think multiple data sources for timelines). The Registry also indicated access to files no longer on the system, as well as files that were on other media.
I'm really looking forward to the book coming out for two reasons...one is to see it and hold it. The other is to see what folks think, in hopes that the content will spur discussion (what else is needed) as well as a greater move toward recognizing the Registry as a valuable forensic resource.
FIRST
I recently attended a portion of a FIRST technical colloquium put on by IBM. Thanks to Richard Bejtlich for sponsoring me so I could attend.
I saw David Bianco (I'd swear that David is Cory Altheide's fraternal twin...) from Richard's team at GE talk about what they were doing, and the biggest take-away for me was the fact that they collect what's practical, as opposed to everything that's possible. They've got a phased approach to their network monitoring coverage, which has been prioritized; much like the Great Wall, they don't so much look at what's coming in as what's trying to go out of their infrastructure in the first phase of their rollout. This clearly demonstrates considerable thought having been put into their approach, taking into account what needs to be covered, staffing levels, etc., and coordinating all of these resources.
In part, this is something of a breath of fresh air when applied to the IR/DF communities. Too often, I think, we tend to take an "I need EVERYTHING possible" approach, and end up losing site of our goals. I really liked what David said about getting everything practical, as I can really see how it applies to the IR/DF field. Have you ever seen someone who will arrive on-site as a responder and state their strategy is to image everything? By the time you're done imaging, the customer is no longer interested in your findings, as they're likely fined or out of business.
Another thing that came out of the discussion surrounding the presentation was that they have a tiered approach for their analysts, with a progressive career path, so that analysts coming in at a particular level have goals that they can strive for in order to progress to the next level. This is a different view than what I had seen when I got into the security industry in 1997, and I think that its an excellent approach.
Again, thanks, Richard. I was saddened to not see Eoghan Casey at the colloquium.
As I've mentioned, Windows Registry Forensics is nearing completion (I'm reviewing the proofs now...) and according to Syngress, will be available in January. When something like this is coming out, as with WFA 2/e, the biggest question I tend to get is, "Did you cover the differences/changes in Windows versions?"
Most times, I'm taken aback by this question. I was at the CSI 2010 conference recently, and went by the Syngress table. I talked to someone who was looking at a copy of WFA 2/e, and once he realized that I was the author, he asked me that question. In order to get a better idea how to answer that question, I turned it around and asked him, "...like what?" To that, I got a blank stare in response.
I think...and please, correct me if I'm wrong here...but the real, underlying question is, what are the new sources and locations of potentially valuable data?
In many ways, this is something of a loaded question...because, yes, there are some things that are different between versions of Windows, and in particular between the venerable Windows XP and the shiny new Windows 7. But I could sit here for the better part of the day talking about the differences and never, not once, hit on anything of value to you or to your examinations. Some file paths and Registry locations have changed...while some haven't. Some file formats have changed, while new ones have been added. Some of the new file types in Windows 7...for example, sticky notes...are a bit questionable when it comes to their potential value as evidence.
My suggestion to the community is that if you want to see this kind of thing, start talking. What good does it do to stand there asking "...did you cover all of the changes?" AFTER the book has been written and published, and you're holding it in your hands (with your thumb on the table of contents)? Seriously. If you've got a concern, ask someone. I think you'll be surprised...if nothing else, that you're not the only person with that question. Sometimes, that's all it takes...
Registry Analysis
Speaking of working on the book (the proofs, really), one of the things that really intrigues me about Registry analysis is...well...Registry analysis.
One of the most valuable uses for Registry analysis that I've found is that you can go into the Registry and see historical access to a range of resources...USB removable storage devices (thumb drives, digital cameras, etc.), network shares, remote systems (via RDP or VNC), files that no longer exist on the system, etc. In many cases, you can tie a good deal of this activity to a user, as well as to a specific time frame. You can see what a user searched for on the system.
I've performed examinations of systems where there was a question regarding digital images...we'll just leave it at that (most of us know where I'm going with this...). Someone had claimed that the images had been put on the system by malware, and yet the Registry clearly showed not only access to the files in question, but also showed an association with a specific viewing application, and time stamps indicating when the files had been accessed. These time stamps from the Registry corresponded to file system metadata, as well as metadata from Prefetch files associated with the viewing application(s) (think multiple data sources for timelines). The Registry also indicated access to files no longer on the system, as well as files that were on other media.
I'm really looking forward to the book coming out for two reasons...one is to see it and hold it. The other is to see what folks think, in hopes that the content will spur discussion (what else is needed) as well as a greater move toward recognizing the Registry as a valuable forensic resource.
FIRST
I recently attended a portion of a FIRST technical colloquium put on by IBM. Thanks to Richard Bejtlich for sponsoring me so I could attend.
I saw David Bianco (I'd swear that David is Cory Altheide's fraternal twin...) from Richard's team at GE talk about what they were doing, and the biggest take-away for me was the fact that they collect what's practical, as opposed to everything that's possible. They've got a phased approach to their network monitoring coverage, which has been prioritized; much like the Great Wall, they don't so much look at what's coming in as what's trying to go out of their infrastructure in the first phase of their rollout. This clearly demonstrates considerable thought having been put into their approach, taking into account what needs to be covered, staffing levels, etc., and coordinating all of these resources.
In part, this is something of a breath of fresh air when applied to the IR/DF communities. Too often, I think, we tend to take an "I need EVERYTHING possible" approach, and end up losing site of our goals. I really liked what David said about getting everything practical, as I can really see how it applies to the IR/DF field. Have you ever seen someone who will arrive on-site as a responder and state their strategy is to image everything? By the time you're done imaging, the customer is no longer interested in your findings, as they're likely fined or out of business.
Another thing that came out of the discussion surrounding the presentation was that they have a tiered approach for their analysts, with a progressive career path, so that analysts coming in at a particular level have goals that they can strive for in order to progress to the next level. This is a different view than what I had seen when I got into the security industry in 1997, and I think that its an excellent approach.
Again, thanks, Richard. I was saddened to not see Eoghan Casey at the colloquium.
Monday, November 01, 2010
Thoughts on Analysis, Information Sharing, and Presentations
Since June of this year, I've attended a couple of conferences, not only presenting but also attending several presentations. As with any conference, presentations tend to vary with the background and experience of the author. By experience, I don't so much mean with the experience the author has in the topic they're presenting on, but more so with developing presentations specific to the audience, public speaking, etc.
One of the questions I ask myself when both creating and giving a presentation, as well as attending one, is "how is this immediately valuable and useful to me?" Often times, we attend a presentation that may have some great information, but the question then becomes, okay, but how to I use this? How do I most quickly/immediately turn this information around and use it on a case or examination?
I'm sure that a lot of other folks feel the same way, particularly after having talked about this very subject after a presentation or discussion. I've also seen this enough to add this sort of approach to my books, starting with WFA 2/e and progressing even more so into Windows Registry Forensics. With a lot of what's going on in our community, it's vitally important that analysts be able to get up from a presentation or talk, and be able to put what they've learned in a technical presentation or lab into practice. If that isn't the case...what's the point?
This is critically important when you're talking about analysis techniques, which is particularly where we need to innovate. Data is always going to be data, and it's always going to be there. There's been discussion about triaging systems, due in part to the massive increases in storage and the amount of time it takes to acquire and analyze all of that (especially acquire). So whether you're talking about browser forensics or
Innovation in Analysis
How many folks out there use RegRipper? How about using RegRipper for malware detection or analysis? Seriously.
Bear with me on this...it probably wouldn't occur to most folks to use something like RegRipper for malware detection, looking into an acquired image, or a system accessed via F-Response. However, I (and others) have used this approach time and again to our benefit.
Consider Conficker. Microsoft cites five variants. In each case, when the next variant first came on the scene, the executable file was not detected by most commercial AV tools. However, there were some consistencies across the malware family, including not just artifacts (ie, disabling system functionality) but also in the persistence mechanism.
I had the distinct honor of reviewing on of the chapters for the new book, The Malware Analyst's Cookbook, and in that chapter, the use of RegRipper was discussed. MHL and his co-authors had written several plugins for use in their work (included in the book) and to be honest, they were innovative.
Okay, so you're probably looking at this so far and thinking, yeah, but that's for malware you know about. Okay, sure, I can go with that. But here's the deal...while you may not have seen all malware, or at least a great deal of it, but what are the chances that within a large group or community of forensic and malware analysts, a LOT of malware has been seen and analyzed? Of those, their artifacts and persistence mechanisms will likely have been identified (Zeus, or ZBot falls into this category) and be worthy of a plugin.
Consider malware based on PoisonIvy. Yes, it's polymorphic, which for most of us, is going to mean that AV scanners are going to have minimal effect in detecting this stuff. However, keep in mind the four characteristics of malware...the persistence mechanism is an example of Jesse Kornblum's "rootkit paradox"; in short, most malware will want to run, but will also want to remain persistent. As it turns out, PoisonIvy isn't the only malware that uses the Registry Installed Components as the persistence mechanism.
Institutional Knowledge
How many of us use the institutional knowledge developed on previous cases/engagements on any new analysis that comes in? Most of us are going to raise our hands and say, "I do that all the time."
Now, how many of us make use of the institutional knowledge developed by other analysts, such as other team members?
Tools like RegRipper (and pretty much any tool that has some level of extensibility, including EnCase and ProDiscover) provide for sharing of institutional knowledge, but only insofar as that institutional knowledge is documented.
So What?
I'm sad to say that not all of us will ever see everything, particularly when it comes to IR and digital forensics analysis. For myself, I know that I haven't seen everything...I've seen some things several times, I've been on engagements that never where, but I haven't seen everything. Expand this to include any 5, 10, 50, or 500 analysts you want, and while it may seem that across all of us, we've seen a lot, the question then becomes...how much of that have we shared with others, or each other.
The issues the community faces are not going away. Increases in things like storage space, sophistication and proliferation of malware and compromises/intrusions, AV scanners becoming less and less of a reliable resource, to name a few. I think that most of us are familiar with these issues. So what do we do about all these?
CyberSpeak
Ovie's on a roll...don't miss the new CyberSpeak podcast! Ovie has an interview regarding triaging systems...talk about timely! ;-)
One of the questions I ask myself when both creating and giving a presentation, as well as attending one, is "how is this immediately valuable and useful to me?" Often times, we attend a presentation that may have some great information, but the question then becomes, okay, but how to I use this? How do I most quickly/immediately turn this information around and use it on a case or examination?
I'm sure that a lot of other folks feel the same way, particularly after having talked about this very subject after a presentation or discussion. I've also seen this enough to add this sort of approach to my books, starting with WFA 2/e and progressing even more so into Windows Registry Forensics. With a lot of what's going on in our community, it's vitally important that analysts be able to get up from a presentation or talk, and be able to put what they've learned in a technical presentation or lab into practice. If that isn't the case...what's the point?
This is critically important when you're talking about analysis techniques, which is particularly where we need to innovate. Data is always going to be data, and it's always going to be there. There's been discussion about triaging systems, due in part to the massive increases in storage and the amount of time it takes to acquire and analyze all of that (especially acquire). So whether you're talking about browser forensics or
Innovation in Analysis
How many folks out there use RegRipper? How about using RegRipper for malware detection or analysis? Seriously.
Bear with me on this...it probably wouldn't occur to most folks to use something like RegRipper for malware detection, looking into an acquired image, or a system accessed via F-Response. However, I (and others) have used this approach time and again to our benefit.
Consider Conficker. Microsoft cites five variants. In each case, when the next variant first came on the scene, the executable file was not detected by most commercial AV tools. However, there were some consistencies across the malware family, including not just artifacts (ie, disabling system functionality) but also in the persistence mechanism.
I had the distinct honor of reviewing on of the chapters for the new book, The Malware Analyst's Cookbook, and in that chapter, the use of RegRipper was discussed. MHL and his co-authors had written several plugins for use in their work (included in the book) and to be honest, they were innovative.
Okay, so you're probably looking at this so far and thinking, yeah, but that's for malware you know about. Okay, sure, I can go with that. But here's the deal...while you may not have seen all malware, or at least a great deal of it, but what are the chances that within a large group or community of forensic and malware analysts, a LOT of malware has been seen and analyzed? Of those, their artifacts and persistence mechanisms will likely have been identified (Zeus, or ZBot falls into this category) and be worthy of a plugin.
Consider malware based on PoisonIvy. Yes, it's polymorphic, which for most of us, is going to mean that AV scanners are going to have minimal effect in detecting this stuff. However, keep in mind the four characteristics of malware...the persistence mechanism is an example of Jesse Kornblum's "rootkit paradox"; in short, most malware will want to run, but will also want to remain persistent. As it turns out, PoisonIvy isn't the only malware that uses the Registry Installed Components as the persistence mechanism.
Institutional Knowledge
How many of us use the institutional knowledge developed on previous cases/engagements on any new analysis that comes in? Most of us are going to raise our hands and say, "I do that all the time."
Now, how many of us make use of the institutional knowledge developed by other analysts, such as other team members?
Tools like RegRipper (and pretty much any tool that has some level of extensibility, including EnCase and ProDiscover) provide for sharing of institutional knowledge, but only insofar as that institutional knowledge is documented.
So What?
I'm sad to say that not all of us will ever see everything, particularly when it comes to IR and digital forensics analysis. For myself, I know that I haven't seen everything...I've seen some things several times, I've been on engagements that never where, but I haven't seen everything. Expand this to include any 5, 10, 50, or 500 analysts you want, and while it may seem that across all of us, we've seen a lot, the question then becomes...how much of that have we shared with others, or each other.
The issues the community faces are not going away. Increases in things like storage space, sophistication and proliferation of malware and compromises/intrusions, AV scanners becoming less and less of a reliable resource, to name a few. I think that most of us are familiar with these issues. So what do we do about all these?
CyberSpeak
Ovie's on a roll...don't miss the new CyberSpeak podcast! Ovie has an interview regarding triaging systems...talk about timely! ;-)
Friday, October 29, 2010
Analysis Techniques
Now and again, it's a good idea to revisit old thoughts and ideas, to dredge them up again and expose them to the light of day. One of the things that I have spent a lot of time thinking about is the analysis techniques that I'm using during examinations, and in particular taking a step forward and seeing how those techniques stack up against some of the threats and issues that are being seen.
First, a caveat...a lot of what I think (and sometimes talk) about focuses on disk analysis. This is due to the realities of the work I (and others) do. Was a responder, many times, all I have access to is a disk image. Or, as is often the case now, I focus on disk analysis because I'm part of a team that includes folks who are way smarter and far more capable than I am in network, memory and malware analysis. So the disk stuff is a piece of the puzzle, and should be treated as such, even if it's the only piece you have.
Analysis
So, there are a couple of general techniques I tend to use in analysis, and I often start with timeline analysis. This is a great analysis technique to use due to the fact that when you build a timeline from multiple data sources on and from within a system, you give yourself two things that you don't normally have through more traditional analysis techniques...context, and a greater relative level of confidence in your data. By context, we aren't simply seeing an event such as a file being created or changed...we're seeing other surrounding events that can (and often do) indicate what lead to that event occurring. The multiple data sources included in a timeline provide a great deal of information; Event Logs may show us a user login, Registry contents may provide additional indications of that login, we may see indicators of web browsing activity, perhaps opening an email attachment, etc...all of which may provide us with the context of the event in which we are most interested.
As to the overall relative level of confidence in our data, we have to understand that all data sources have a relative level of confidence associated with each of them. For example, from Chris's post, we know that the relative confidence level of the time stamps within the $STANDARD_INFORMATION attributes within the MFT (and file system) is (or should be) low. That's because these values are fairly easily changed, often through "time stomping", so that the MACB times (particularly the "B" time, or creation date of the file) do not fall within the initial timeframe of the incident. However, the time stamps within the $FILE_NAME attributes can provide us with a greater level of confidence in the data source (MFT, in this case). By adding other data sources (Event Log, Registry, Prefetch file metadata, etc.), particularly data source whose time stamps are not so easily modified (such as Registry key LastWrite times), we can elevate our relative confidence level in the data.
Another aspect of this is that by adding multiple sources, we will begin to see patterns in the data and also begin to see where there are gaps in that data.
This is particularly important as intrusions and malware are very often the least frequency of occurrence on a system. Credit for this phrase goes to Pete Silberman of Mandiant, and it's an extremely important concept to understand, particularly when it comes to timeline analysis. In short, many times analysts will look for large tool kits or spikes in the event volume as an indication of compromise. However, most often, this simply is not the case...spikes in activity in a timeline will correspond to an operating system or application update, Restore Point being created, etc. So, in short, intrusions and even malware have taken a turn toward minimalization on systems, so looking for spikes in activity likely won't get you anywhere. This is not to say that if your FTP server is turned into a warez server, you won't see a spike in activity or event volume...rather, the overall effects of an incident are most likely minimized. A user clicks a link or an application is exploited, something is uploaded to the system, and data gets exfiltrated at some point...disk forensics artifacts are minimized, particularly if the data is exfiltrated without ever writing it to disk.
Timeline Creation
When creating a timeline, I tend to take what most analysts consider a very manual process, in that I do not use tools that simply sweep through an image and collect all possible timeline data. However, there is a method to my madness, which can be seen in part in Chris's Sniper Forensics presentation. I tend to take a targeted approach, adding the information that is necessary to complete the picture. For example, when analyzing a system that had been compromised via SQL injection, I included the file system metadata and only the web server logs that contained the SQL injection attack information. There was no need to include user information (Registry, index.dat, etc.); in fact, doing so would have added considerable noise to the timeline, and the extra data would have required significantly more effort to analyze and parse through in order to find what I was looking for.
Many times when creating a timeline, I don't want to see everything all at once. When examining a Windows system, there are so many possible data sources that filling in the timeline with the appropriate sources in an iterative manner is...for me...more productive and efficient that loading everything up into the timeline all at once, and parsing things out from there. If a system had a dozen user profiles, but only one or two is of interest, I'm not about to populate the timeline with the LastWrite times of all the keys in the other user's NTUSER.DAT hives. Also, when you get to more recent versions of Windows, specific keys in the USRCLASS.DAT hive become more important, and I don't want to add the LastWrite time of all of those keys when I'm more interested in some specific values from specific keys.
Part of the iterative approach in developing the timeline is looking at the data you have available and seeing gaps. Some gaps may be due to the fact that the data no longer exists...file last access/modified times may be updated to more recent times, Event Logs may "roll over", etc. Looking at gaps has a lot to do with your analysis goals and the questions you're trying to answer, and knowing what you would need to fill that gap. Many times, we may not have access to a direct artifact (such as an event record with ID 528, indicating a login...), but we may be able to fill that gap (at least partially) with indirect artifacts (i.e., UserAssist key entries, etc.).
Feedback Loop
Timeline analysis provides a view of a system that, in most cases, an analyst wouldn't get any other way. This leads to discovering things that wouldn't otherwise be found, due in part to the view enabled via context. This context can also lead to finding those much quicker. Once you've done this, its critical for future exams that you take what you have learned and roll it back into your analysis process. After all, what good would it be for anyone for you to simply let that valuable institutional knowledge disappear? Retaining that institutional knowledge allows you to fine-tune and hone your analysis process.
Consider folks that work on teams...say, there's a team of 12 analysts. One analyst finds something new after 16 hrs of analysis. If every analyst were to take 16 hrs to find the same thing, then by not sharing what you found, your team consumes an additional 176 (16 x 11) hrs. That's not terribly efficient, particularly when it could be obviated by a 30 minute phone call. However, if you share your findings with the rest of the team, they will know to look for this item. If you share it with them via a framework such as a forensic scanner (see the Projects section of this post), similar to RegRipper (for example), then looking for that same set of artifacts is now no longer something they have to memorize and remember, as it takes just seconds to check for them via the scanner. All that's really needed is that your image intake process is modified slightly; when the image comes in, make your working copy, verify the file system of the copy, and then run the forensic scanner. Using the results, you can determine whether or not things that you've seen already were found, removing the need to remember all of the different artifacts and freeing your analysts up some in-depth analysis.
So What?
So why does all this matter? Why is it important? The short answer is that things aren't going to get easier, and if we (analysts) don't take steps to improve what we do, we're going to quickly fall further behind. We need to find and use innovative analysis techniques that allow us to look at systems and the available data in different ways, adding context and increasing our relative level of confidence in the data, particularly as some data becomes less and less reliable. We also need to consider and explore previously un- or under-utilized data sources, such as the Registry.
Consider malware detection...some folks may think that you can't use RegRipper or tools like it for something like finding malware, but I would suggest that that simply isn't the case. Consider Conficker...while the different variants escaped detection via AV scanners, there were consistent Registry artifacts across the entire family. And it's not just me...folks like MHL (and his co-authors) have written RegRipper plugins (if you deal with malware at all, you MUST get a copy of their book...) to assist them in their analysis.
The same thing can be said of intrusions...understanding Windows from a system perspective, and understanding how different artifacts are created or modified can show us what we need to focus on, and what data sources we need to engage for both direct and indirect artifacts. But these techniques are not limited to just malware and intrusions...they can be used similarly used to analyze other incidents, as well.
First, a caveat...a lot of what I think (and sometimes talk) about focuses on disk analysis. This is due to the realities of the work I (and others) do. Was a responder, many times, all I have access to is a disk image. Or, as is often the case now, I focus on disk analysis because I'm part of a team that includes folks who are way smarter and far more capable than I am in network, memory and malware analysis. So the disk stuff is a piece of the puzzle, and should be treated as such, even if it's the only piece you have.
Analysis
So, there are a couple of general techniques I tend to use in analysis, and I often start with timeline analysis. This is a great analysis technique to use due to the fact that when you build a timeline from multiple data sources on and from within a system, you give yourself two things that you don't normally have through more traditional analysis techniques...context, and a greater relative level of confidence in your data. By context, we aren't simply seeing an event such as a file being created or changed...we're seeing other surrounding events that can (and often do) indicate what lead to that event occurring. The multiple data sources included in a timeline provide a great deal of information; Event Logs may show us a user login, Registry contents may provide additional indications of that login, we may see indicators of web browsing activity, perhaps opening an email attachment, etc...all of which may provide us with the context of the event in which we are most interested.
As to the overall relative level of confidence in our data, we have to understand that all data sources have a relative level of confidence associated with each of them. For example, from Chris's post, we know that the relative confidence level of the time stamps within the $STANDARD_INFORMATION attributes within the MFT (and file system) is (or should be) low. That's because these values are fairly easily changed, often through "time stomping", so that the MACB times (particularly the "B" time, or creation date of the file) do not fall within the initial timeframe of the incident. However, the time stamps within the $FILE_NAME attributes can provide us with a greater level of confidence in the data source (MFT, in this case). By adding other data sources (Event Log, Registry, Prefetch file metadata, etc.), particularly data source whose time stamps are not so easily modified (such as Registry key LastWrite times), we can elevate our relative confidence level in the data.
Another aspect of this is that by adding multiple sources, we will begin to see patterns in the data and also begin to see where there are gaps in that data.
This is particularly important as intrusions and malware are very often the least frequency of occurrence on a system. Credit for this phrase goes to Pete Silberman of Mandiant, and it's an extremely important concept to understand, particularly when it comes to timeline analysis. In short, many times analysts will look for large tool kits or spikes in the event volume as an indication of compromise. However, most often, this simply is not the case...spikes in activity in a timeline will correspond to an operating system or application update, Restore Point being created, etc. So, in short, intrusions and even malware have taken a turn toward minimalization on systems, so looking for spikes in activity likely won't get you anywhere. This is not to say that if your FTP server is turned into a warez server, you won't see a spike in activity or event volume...rather, the overall effects of an incident are most likely minimized. A user clicks a link or an application is exploited, something is uploaded to the system, and data gets exfiltrated at some point...disk forensics artifacts are minimized, particularly if the data is exfiltrated without ever writing it to disk.
Timeline Creation
When creating a timeline, I tend to take what most analysts consider a very manual process, in that I do not use tools that simply sweep through an image and collect all possible timeline data. However, there is a method to my madness, which can be seen in part in Chris's Sniper Forensics presentation. I tend to take a targeted approach, adding the information that is necessary to complete the picture. For example, when analyzing a system that had been compromised via SQL injection, I included the file system metadata and only the web server logs that contained the SQL injection attack information. There was no need to include user information (Registry, index.dat, etc.); in fact, doing so would have added considerable noise to the timeline, and the extra data would have required significantly more effort to analyze and parse through in order to find what I was looking for.
Many times when creating a timeline, I don't want to see everything all at once. When examining a Windows system, there are so many possible data sources that filling in the timeline with the appropriate sources in an iterative manner is...for me...more productive and efficient that loading everything up into the timeline all at once, and parsing things out from there. If a system had a dozen user profiles, but only one or two is of interest, I'm not about to populate the timeline with the LastWrite times of all the keys in the other user's NTUSER.DAT hives. Also, when you get to more recent versions of Windows, specific keys in the USRCLASS.DAT hive become more important, and I don't want to add the LastWrite time of all of those keys when I'm more interested in some specific values from specific keys.
Part of the iterative approach in developing the timeline is looking at the data you have available and seeing gaps. Some gaps may be due to the fact that the data no longer exists...file last access/modified times may be updated to more recent times, Event Logs may "roll over", etc. Looking at gaps has a lot to do with your analysis goals and the questions you're trying to answer, and knowing what you would need to fill that gap. Many times, we may not have access to a direct artifact (such as an event record with ID 528, indicating a login...), but we may be able to fill that gap (at least partially) with indirect artifacts (i.e., UserAssist key entries, etc.).
Feedback Loop
Timeline analysis provides a view of a system that, in most cases, an analyst wouldn't get any other way. This leads to discovering things that wouldn't otherwise be found, due in part to the view enabled via context. This context can also lead to finding those much quicker. Once you've done this, its critical for future exams that you take what you have learned and roll it back into your analysis process. After all, what good would it be for anyone for you to simply let that valuable institutional knowledge disappear? Retaining that institutional knowledge allows you to fine-tune and hone your analysis process.
Consider folks that work on teams...say, there's a team of 12 analysts. One analyst finds something new after 16 hrs of analysis. If every analyst were to take 16 hrs to find the same thing, then by not sharing what you found, your team consumes an additional 176 (16 x 11) hrs. That's not terribly efficient, particularly when it could be obviated by a 30 minute phone call. However, if you share your findings with the rest of the team, they will know to look for this item. If you share it with them via a framework such as a forensic scanner (see the Projects section of this post), similar to RegRipper (for example), then looking for that same set of artifacts is now no longer something they have to memorize and remember, as it takes just seconds to check for them via the scanner. All that's really needed is that your image intake process is modified slightly; when the image comes in, make your working copy, verify the file system of the copy, and then run the forensic scanner. Using the results, you can determine whether or not things that you've seen already were found, removing the need to remember all of the different artifacts and freeing your analysts up some in-depth analysis.
So What?
So why does all this matter? Why is it important? The short answer is that things aren't going to get easier, and if we (analysts) don't take steps to improve what we do, we're going to quickly fall further behind. We need to find and use innovative analysis techniques that allow us to look at systems and the available data in different ways, adding context and increasing our relative level of confidence in the data, particularly as some data becomes less and less reliable. We also need to consider and explore previously un- or under-utilized data sources, such as the Registry.
Consider malware detection...some folks may think that you can't use RegRipper or tools like it for something like finding malware, but I would suggest that that simply isn't the case. Consider Conficker...while the different variants escaped detection via AV scanners, there were consistent Registry artifacts across the entire family. And it's not just me...folks like MHL (and his co-authors) have written RegRipper plugins (if you deal with malware at all, you MUST get a copy of their book...) to assist them in their analysis.
The same thing can be said of intrusions...understanding Windows from a system perspective, and understanding how different artifacts are created or modified can show us what we need to focus on, and what data sources we need to engage for both direct and indirect artifacts. But these techniques are not limited to just malware and intrusions...they can be used similarly used to analyze other incidents, as well.
Monday, October 18, 2010
Updates
CyberSpeak is Back!
Ovie returns, sans Bret, to talk about browser forensics, and more...check it out!
StuxNet
ESET's paper, Stuxnet Under the Microscope, has so far been an excellent read. It's 72 pages, but there are a lot of graphics. ;-) Take a look...there's some good info there.
Addendum: Check out Symantec's Stuxnet dossier, as well...
XP Restore Points
A bit ago, I'd reached to some friends at Microsoft regarding the structure of the drivetable.txt file in XP Restore Points. I received a response recently, and I'm posting it here with a big thanks to Jim for providing it and for the permission to post it:
C:\/\\?\Volume{181b2120-e4ac-11de-a517-806d6172696f}\ 3b 0 15604/ <>
If you see the flags field with a nonzero value, this is what they mean…
0x01 SR_DRIVE_ACTIVE
0x02 SR_DRIVE_SYSTEM
0x04 SR_DRIVE_COMPRESSED
0x08 SR_DRIVE_MONITORED
0x10 SR_DRIVE_NTFS
0x20 SR_DRIVE_PARTICIPATE
0x40 SR_DRIVE_FROZEN
0x80 SR_DRIVE_READONLY
0x100 SR_DRIVE_ERROR
The reason I'd asked about this was that I'd seen the question posted by LE and hadn't seen a response. Again, thanks to Jim for sussing this one out...
Speaking of Exploits...
Both Brian Krebs and the MMPC are reporting an increase in exploits to Java (not JavaScript). This is easy for both of them to report, because the solution is simply to update your Java installation. However, what's not being mentioned anywhere is what that looks like on a system. Should forensic analysts be looking for .jar files in the browser cache? Following one of the vulnerability links from Brian's post takes us to a CVE entry that starts with:
Unspecified vulnerability in the Java Runtime Environment component in Oracle Java SE and Java for Business 6 Update 18 and 5.0 Update 23 allows remote attackers to affect...
Unspecified? So how do I know if I've been affected by it? It's relatively easy for me to check to see if I'm vulnerable...I just check my version of Java. But how would I know if I've already been affected by this? More importantly, how does an analyst examining a system figure out if this is the initial infection vector?
This isn't just an idle question I'm asking. This potentially affects victims subject to PCI investigations, and a wide range of other compliance issues.
Ovie returns, sans Bret, to talk about browser forensics, and more...check it out!
StuxNet
ESET's paper, Stuxnet Under the Microscope, has so far been an excellent read. It's 72 pages, but there are a lot of graphics. ;-) Take a look...there's some good info there.
Addendum: Check out Symantec's Stuxnet dossier, as well...
XP Restore Points
A bit ago, I'd reached to some friends at Microsoft regarding the structure of the drivetable.txt file in XP Restore Points. I received a response recently, and I'm posting it here with a big thanks to Jim for providing it and for the permission to post it:
C:\/\\?\Volume{181b2120-e4ac-11de-a517-806d6172696f}\ 3b 0 15604
If you see the flags field with a nonzero value, this is what they mean…
0x01 SR_DRIVE_ACTIVE
0x02 SR_DRIVE_SYSTEM
0x04 SR_DRIVE_COMPRESSED
0x08 SR_DRIVE_MONITORED
0x10 SR_DRIVE_NTFS
0x20 SR_DRIVE_PARTICIPATE
0x40 SR_DRIVE_FROZEN
0x80 SR_DRIVE_READONLY
0x100 SR_DRIVE_ERROR
The reason I'd asked about this was that I'd seen the question posted by LE and hadn't seen a response. Again, thanks to Jim for sussing this one out...
Speaking of Exploits...
Both Brian Krebs and the MMPC are reporting an increase in exploits to Java (not JavaScript). This is easy for both of them to report, because the solution is simply to update your Java installation. However, what's not being mentioned anywhere is what that looks like on a system. Should forensic analysts be looking for .jar files in the browser cache? Following one of the vulnerability links from Brian's post takes us to a CVE entry that starts with:
Unspecified vulnerability in the Java Runtime Environment component in Oracle Java SE and Java for Business 6 Update 18 and 5.0 Update 23 allows remote attackers to affect...
Unspecified? So how do I know if I've been affected by it? It's relatively easy for me to check to see if I'm vulnerable...I just check my version of Java. But how would I know if I've already been affected by this? More importantly, how does an analyst examining a system figure out if this is the initial infection vector?
This isn't just an idle question I'm asking. This potentially affects victims subject to PCI investigations, and a wide range of other compliance issues.
Friday, October 15, 2010
Back from WACCI
So I got up this morning to find myself back from the WACCI conference, which is still going on, with today being the final day.
First, I want to thank Cindy and Drew for doing such a great job setting up and organizing this conference, which is geared toward computer crime investigators. The conference venue was spacious and very close to the hotel, and well organized. As with many conferences, there were often two (or more) interesting talks scheduled at the same time.
I also want to thank those who attended for...attending. One of the things I really like about conferences is the networking opportunity. I got to see some friends, like Ovie Carroll, Ken Pryor, and Mark McKinnon. I also got to make some new friends and meet some great people...Sam Brothers, Brad Garnett, Mark Lachinet, and Fergus Toolan, to name a very few.
WACCI brought together private industry analysts, LE, and academics, all in one place. This is a smallish, regional conference, but these kinds of conferences are important, as they foster relationships that lead to sharing...which was the central point of my keynote, and as it turns out, an important element of Ovie's, as well.
On Tuesday, we started off with a welcome message to the conference from the Dane County sheriff, had lunch, and then kicked off into Ovie's keynote. Having been an instructor at TBS back in the '90s, I am very familiar with presentations given right after lunch, during "the death hour". Ovie is a very dynamic speaker, and his presentation was very engaging, not only with the movement and transitions on the slides, but more importantly, with the content. He made some excellent points throughout the presentation, particularly with respect to sharing information and intel amongst LE.
For my keynote...which was the "zombie hour", as I followed both lunch and Ovie (I KID!!!)...I opted to go commando. That's right...no slides. What I tried to engage the audience in was a discussion regarding the need not just for sharing, but simply communications between LE and the private sector. Folks in the private sector, such as myself, Chris Pogue, etc., tend to see a lot of different things and run across (and very often solve) some of the same challenges met by LE. As such, there is really no need for LE to spend the time re-solving technical problems that have already been addressed by others. Reaching out can tend to decrease the amount of time needed to complete a case while increasing the volume/quality of information/data retrieved. The "Trojan Defense" comes to mind. Remember, those of us in the private sector don't just deal with intrusions and compromises, we address issues and solve problems...it just happens that the folks who call us have intrusion issues. Many of us are more than willing to assist local LE with issues where we can, which is something Chris and Maj Carole Newell talked about at the SANS Forensic Summit this past summer.
I didn't expect to solve any problems with this discussion. Instead, I wanted to engage others in a discussion about how we could engage in more sharing and communication between the sectors. For me personally, success is measured in having one member of LE who hadn't reached out before overcome those often self-imposed obstacles and share, either by asking a question or contributing something (white paper, finding, etc.).
Perhaps the most significant thing to come out of the discussion is the need for a central repository of some kind where folks (LE in particular) can go for credible information, and even provide information in a manner that protects anonymity (although there was discussion that suggested that anonymity is inversely proportional to credibility) and privacy of the poster. The MITRE CVE was suggested as a model. One of the issues I've heard time and again is that the information is out there, and the problem is that it's out there...how do you find it, and how do you find the credible information? In most cases, I agree with that, but I also think that sometimes the issue is a lack of knowledge, or perhaps something else. During the conference, several questions came up (mostly during the more social parts of the conference) where someone would say, "I've been looking all over for information on this...", and within seconds, someone else would get on their computer or smartphone, call up Google, and find highly relevant links. But that's the first step...the sharing, the asking.
As a side note to this, I've had an opportunity to start discussing something like this, a forensic artifact repository, with Troy Larson of Microsoft. However, if you haven't seen it yet, be sure to check out ForensicArtifacts.com...perhaps something like this is a start, and what's needed are forums...some open, some vetted...for discussions.
Ken Pryor has already had his comments about the first day of WACCI posted on the SANS Forensic Blog. Be sure to check these and other comments out for varying views on the conference and presentations.
I'll admit that I only attended one presentation, as I spent a lot of time engaging and networking with folks at the conference, including the vendors (Cellebrite, in particular). In particular, one of the most vocal attendees during my keynote (besides Cindy!!) was Sam Brothers. Sam is not only well-published in mobile forensics, but he's also an amazing magician, regaling us with some truly incredible card tricks! Listening and talking to Sam, I know who I'm going to go toif when I encounter any forensic issues with mobile devices!
In closing, I just want to thank Cindy and Drew again for putting together such a great conference, and Cindy in particular for inviting me (and the rest of us) to her home for a great social event. I also want to thank Mark McKinnon for sharing such wonderful gifts with us...Bells Two-Hearted Ale (to which Sam whispered, "this is awesome!!"), steak brats, and Michigan cherry gourmet coffee. A great big "THANK YOU" to everyone who attended and made this conference a great success!
First, I want to thank Cindy and Drew for doing such a great job setting up and organizing this conference, which is geared toward computer crime investigators. The conference venue was spacious and very close to the hotel, and well organized. As with many conferences, there were often two (or more) interesting talks scheduled at the same time.
I also want to thank those who attended for...attending. One of the things I really like about conferences is the networking opportunity. I got to see some friends, like Ovie Carroll, Ken Pryor, and Mark McKinnon. I also got to make some new friends and meet some great people...Sam Brothers, Brad Garnett, Mark Lachinet, and Fergus Toolan, to name a very few.
WACCI brought together private industry analysts, LE, and academics, all in one place. This is a smallish, regional conference, but these kinds of conferences are important, as they foster relationships that lead to sharing...which was the central point of my keynote, and as it turns out, an important element of Ovie's, as well.
On Tuesday, we started off with a welcome message to the conference from the Dane County sheriff, had lunch, and then kicked off into Ovie's keynote. Having been an instructor at TBS back in the '90s, I am very familiar with presentations given right after lunch, during "the death hour". Ovie is a very dynamic speaker, and his presentation was very engaging, not only with the movement and transitions on the slides, but more importantly, with the content. He made some excellent points throughout the presentation, particularly with respect to sharing information and intel amongst LE.
For my keynote...which was the "zombie hour", as I followed both lunch and Ovie (I KID!!!)...I opted to go commando. That's right...no slides. What I tried to engage the audience in was a discussion regarding the need not just for sharing, but simply communications between LE and the private sector. Folks in the private sector, such as myself, Chris Pogue, etc., tend to see a lot of different things and run across (and very often solve) some of the same challenges met by LE. As such, there is really no need for LE to spend the time re-solving technical problems that have already been addressed by others. Reaching out can tend to decrease the amount of time needed to complete a case while increasing the volume/quality of information/data retrieved. The "Trojan Defense" comes to mind. Remember, those of us in the private sector don't just deal with intrusions and compromises, we address issues and solve problems...it just happens that the folks who call us have intrusion issues. Many of us are more than willing to assist local LE with issues where we can, which is something Chris and Maj Carole Newell talked about at the SANS Forensic Summit this past summer.
I didn't expect to solve any problems with this discussion. Instead, I wanted to engage others in a discussion about how we could engage in more sharing and communication between the sectors. For me personally, success is measured in having one member of LE who hadn't reached out before overcome those often self-imposed obstacles and share, either by asking a question or contributing something (white paper, finding, etc.).
Perhaps the most significant thing to come out of the discussion is the need for a central repository of some kind where folks (LE in particular) can go for credible information, and even provide information in a manner that protects anonymity (although there was discussion that suggested that anonymity is inversely proportional to credibility) and privacy of the poster. The MITRE CVE was suggested as a model. One of the issues I've heard time and again is that the information is out there, and the problem is that it's out there...how do you find it, and how do you find the credible information? In most cases, I agree with that, but I also think that sometimes the issue is a lack of knowledge, or perhaps something else. During the conference, several questions came up (mostly during the more social parts of the conference) where someone would say, "I've been looking all over for information on this...", and within seconds, someone else would get on their computer or smartphone, call up Google, and find highly relevant links. But that's the first step...the sharing, the asking.
As a side note to this, I've had an opportunity to start discussing something like this, a forensic artifact repository, with Troy Larson of Microsoft. However, if you haven't seen it yet, be sure to check out ForensicArtifacts.com...perhaps something like this is a start, and what's needed are forums...some open, some vetted...for discussions.
Ken Pryor has already had his comments about the first day of WACCI posted on the SANS Forensic Blog. Be sure to check these and other comments out for varying views on the conference and presentations.
I'll admit that I only attended one presentation, as I spent a lot of time engaging and networking with folks at the conference, including the vendors (Cellebrite, in particular). In particular, one of the most vocal attendees during my keynote (besides Cindy!!) was Sam Brothers. Sam is not only well-published in mobile forensics, but he's also an amazing magician, regaling us with some truly incredible card tricks! Listening and talking to Sam, I know who I'm going to go to
In closing, I just want to thank Cindy and Drew again for putting together such a great conference, and Cindy in particular for inviting me (and the rest of us) to her home for a great social event. I also want to thank Mark McKinnon for sharing such wonderful gifts with us...Bells Two-Hearted Ale (to which Sam whispered, "this is awesome!!"), steak brats, and Michigan cherry gourmet coffee. A great big "THANK YOU" to everyone who attended and made this conference a great success!
Monday, September 27, 2010
Updates
I know, I haven't posted in a while...but then, I haven't really had a lot to post about, as I've been busy completing one project (book) and getting kicked off on another one...
Speaking
I've got a couple of upcoming speaking engagements in the next couple of months...
WACCI - I think I'm giving keynote 2 on Tues; I'm strongly considering using a discussion-style approach (as in "no PPT"), and broaching the subject of engaging and sharing between LE and the private sector in some manner. This is a bit of a sticky wicket, as one cannot simply pontificate on the need for LE to reach to the private sector to engage and share; without being LE, I'm afraid that I'd have little credibility in the matter.
PFIC2010 - I'll be heading to Utah in Nov for a couple of days, to present on "Windows System Forensics". Yeah, I know...lots of room there for me to mess this one up! ;-)
Windows Registry Forensics
I recently finished work on the Windows Registry Forensics book, including sending in the DVD master.
Here's a short description of the chapters:
Ch 1 - This chapter addresses some of what I consider to be the basic concepts of "analysis"; this book is about Registry analysis and as such, I thought it was important to lay out what I see to constitute Registry analysis. This chapter also goes into the purpose and structure of the Registry, in order to build a foundation for the analyst, for the rest of the book.
Ch 2 - This chapter addresses the tools that can be used to perform analysis of the Registry, in both live and post-mortem situations. This is kind of important, I think, because there are issues such as malware infections that really overwhelm both IT admins and responders; identifying Registry artifacts of an infection can allow you to comb the infrastructure using native or custom tools for other infected systems.
Note: This chapter does not address any commercial forensic analysis applications, for the simple reason that I did not have access to any of them, beyond Technology Pathways' ProDiscover.
Ch 3 - This chapter addresses Registry analysis from a system-wide perspective; that is, it addresses the files that compromise the system hives, and what information that is of value to an analyst that can be extracted from the hives. For example, I discuss what information is available from the SAM hive, and also include some tools that you can use to determine if a user has a password, and how you can crack it.
Ch 4 - This chapter addresses analyzing the user's hives.
With chapters 3 and 4, I took a bit of a different approach than I have in the past. Rather than listing key and value after key and value, I provided examples of how the information (key name, key LastWrite time, values, data, etc.) could be and have been used during incident response or during an examination.
The DVD includes a copy of the RegRipper tools (including the Plugin Browser), as well as all of the latest plugins that I've written, as of mid-Sept, 2010.
Open Source
Having finished the Registry book, I'm working diligently on my chapters of Digital Forensics with Open Source Tools, which I'm co-authoring with Cory Altheide (it was Cory's idea, and he's handling the lion's share of the writing).
Projects
I've run across a couple of interesting issues during analysis recently that I wanted to document, and the best way I found to do was to create what I'm referring to as a forensic system scanner, based on tools such as RegRipper and Nessus. The idea is that rather than memorizing the various things I've looked for or found, I can now mount an acquired image as a drive letter, and then run a number of plugins across the image. Much like RegRipper, the plugins can parse the Registry, but what I've done now is included checks for the file system, as well.
I'm designing/writing this scanner to be run against a mounted (via ImDisk, etc.) image, or against a system accessed via F-Response. Given this, it will also work with other mounting methods, such as Windows 7's ability to mount .vhd files. If you have a method for mounting .vmdk files, you could also use that. At this point, I've got a couple/half dozen or so working plugins and things seem to be moving smoothly in that regard. One plugin looks for .tmp files with 'MZ' signatures in the user profiles "Local Settings\Temp" directories...it gets the information about the profile paths from the ProfileList key. That plugin also checks for .exe files with 'MZ' signatures, as well. In both cases, if it finds any such files, it also computes an MD5 hash for each file.
Another plugin checks for a Zeus/Zbot infection. This plugin checks the UserInit value in the Software hive for the addition of "sdra64.exe", as well as checks the system32 directory within the image for the existence of the file. This plugin can be expanded to include any of the other file names that have been used, as well.
Chris Pogue has mentioned seeing the Perfect Key Logger in a number of exams; it is pretty simple and straightforward to write a plugin that checks for this, as well.
As with RegRipper, I can run either individual plugins, or lists of plugins, which I've taken to calling "profiles".
My overall thinking is that there can be a lot of things to look for out there, and if I can codify a check, I don't have to keep trying to remember all of them. God knows I'll get through an exam, deliver the final report, and think, "wow, I forgot to check for this...".
This scanner is NOT meant to completely comprehensive, nor is it meant to replace deep analysis. My goal here is to produce something that can be used as part of an in-processing procedure; get an image, verify it, copy it, then run the scanner against the working copy of the image. The report can then be provided along with either the image, or with selected files extracted from the image, to an analyst. This is intended to be more of a sweeper, but also a force multiplier...think of it; someone writes a check or plugin, and provides it to their team. Now, everyone on the team has the ability to run the same check, even though they don't all see the same thing on every engagement. With a central repository of well-documented plugins, we now have retention of corporate knowledge from each analyst.
Addendum: I was reading this MMPC post regarding Camec.A (they should have entitled the post "Getting a Brazilian"), and it occurred to me that this would be a great example of using the scanner I mentioned above. Specifically, you could easily write a plugin to check for this issue; one way to write it would be to simply check for the DLL files mentioned in the post, and if you find them, get and compare their hashes. Another way to write the plugin would be to add a Registry query for BHOs (RegRipper already has such a plugin), and then check for the files.
Again, once the plugin is written and added to the tool's plugins directory, every system that this is run against would be checked; the analyst running the scan would not need to know (or have memorized) the specifics indicators of the malware.
Speaking
I've got a couple of upcoming speaking engagements in the next couple of months...
WACCI - I think I'm giving keynote 2 on Tues; I'm strongly considering using a discussion-style approach (as in "no PPT"), and broaching the subject of engaging and sharing between LE and the private sector in some manner. This is a bit of a sticky wicket, as one cannot simply pontificate on the need for LE to reach to the private sector to engage and share; without being LE, I'm afraid that I'd have little credibility in the matter.
PFIC2010 - I'll be heading to Utah in Nov for a couple of days, to present on "Windows System Forensics". Yeah, I know...lots of room there for me to mess this one up! ;-)
Windows Registry Forensics
I recently finished work on the Windows Registry Forensics book, including sending in the DVD master.
Here's a short description of the chapters:
Ch 1 - This chapter addresses some of what I consider to be the basic concepts of "analysis"; this book is about Registry analysis and as such, I thought it was important to lay out what I see to constitute Registry analysis. This chapter also goes into the purpose and structure of the Registry, in order to build a foundation for the analyst, for the rest of the book.
Ch 2 - This chapter addresses the tools that can be used to perform analysis of the Registry, in both live and post-mortem situations. This is kind of important, I think, because there are issues such as malware infections that really overwhelm both IT admins and responders; identifying Registry artifacts of an infection can allow you to comb the infrastructure using native or custom tools for other infected systems.
Note: This chapter does not address any commercial forensic analysis applications, for the simple reason that I did not have access to any of them, beyond Technology Pathways' ProDiscover.
Ch 3 - This chapter addresses Registry analysis from a system-wide perspective; that is, it addresses the files that compromise the system hives, and what information that is of value to an analyst that can be extracted from the hives. For example, I discuss what information is available from the SAM hive, and also include some tools that you can use to determine if a user has a password, and how you can crack it.
Ch 4 - This chapter addresses analyzing the user's hives.
With chapters 3 and 4, I took a bit of a different approach than I have in the past. Rather than listing key and value after key and value, I provided examples of how the information (key name, key LastWrite time, values, data, etc.) could be and have been used during incident response or during an examination.
The DVD includes a copy of the RegRipper tools (including the Plugin Browser), as well as all of the latest plugins that I've written, as of mid-Sept, 2010.
Open Source
Having finished the Registry book, I'm working diligently on my chapters of Digital Forensics with Open Source Tools, which I'm co-authoring with Cory Altheide (it was Cory's idea, and he's handling the lion's share of the writing).
Projects
I've run across a couple of interesting issues during analysis recently that I wanted to document, and the best way I found to do was to create what I'm referring to as a forensic system scanner, based on tools such as RegRipper and Nessus. The idea is that rather than memorizing the various things I've looked for or found, I can now mount an acquired image as a drive letter, and then run a number of plugins across the image. Much like RegRipper, the plugins can parse the Registry, but what I've done now is included checks for the file system, as well.
I'm designing/writing this scanner to be run against a mounted (via ImDisk, etc.) image, or against a system accessed via F-Response. Given this, it will also work with other mounting methods, such as Windows 7's ability to mount .vhd files. If you have a method for mounting .vmdk files, you could also use that. At this point, I've got a couple/half dozen or so working plugins and things seem to be moving smoothly in that regard. One plugin looks for .tmp files with 'MZ' signatures in the user profiles "Local Settings\Temp" directories...it gets the information about the profile paths from the ProfileList key. That plugin also checks for .exe files with 'MZ' signatures, as well. In both cases, if it finds any such files, it also computes an MD5 hash for each file.
Another plugin checks for a Zeus/Zbot infection. This plugin checks the UserInit value in the Software hive for the addition of "sdra64.exe", as well as checks the system32 directory within the image for the existence of the file. This plugin can be expanded to include any of the other file names that have been used, as well.
Chris Pogue has mentioned seeing the Perfect Key Logger in a number of exams; it is pretty simple and straightforward to write a plugin that checks for this, as well.
As with RegRipper, I can run either individual plugins, or lists of plugins, which I've taken to calling "profiles".
My overall thinking is that there can be a lot of things to look for out there, and if I can codify a check, I don't have to keep trying to remember all of them. God knows I'll get through an exam, deliver the final report, and think, "wow, I forgot to check for this...".
This scanner is NOT meant to completely comprehensive, nor is it meant to replace deep analysis. My goal here is to produce something that can be used as part of an in-processing procedure; get an image, verify it, copy it, then run the scanner against the working copy of the image. The report can then be provided along with either the image, or with selected files extracted from the image, to an analyst. This is intended to be more of a sweeper, but also a force multiplier...think of it; someone writes a check or plugin, and provides it to their team. Now, everyone on the team has the ability to run the same check, even though they don't all see the same thing on every engagement. With a central repository of well-documented plugins, we now have retention of corporate knowledge from each analyst.
Addendum: I was reading this MMPC post regarding Camec.A (they should have entitled the post "Getting a Brazilian"), and it occurred to me that this would be a great example of using the scanner I mentioned above. Specifically, you could easily write a plugin to check for this issue; one way to write it would be to simply check for the DLL files mentioned in the post, and if you find them, get and compare their hashes. Another way to write the plugin would be to add a Registry query for BHOs (RegRipper already has such a plugin), and then check for the files.
Again, once the plugin is written and added to the tool's plugins directory, every system that this is run against would be checked; the analyst running the scan would not need to know (or have memorized) the specifics indicators of the malware.
Tuesday, September 07, 2010
Another WFA 2/e Review
I received the following comments from Allen Wheeler (a Systems Engineer with Troll Systems) today via email, and with his permission, I wanted to share his comments with you:
I just wanted to tell you how impressed I am with how thoroughly you cover the methods covered in your book. Usually when I pick up a book like this I’m prepared for more questions than when I started but that’s not the case with Windows Forensic Analysis. It’s elegantly worded and easy to follow which is hard to find when it comes to technical books. I read for about 8 hours straight yesterday on a trip back from the east coast and I still didn’t want to put it down. As a long time Windows user, you’ve helped fill in a lot of blanks and I feel like I’ll have a lot more flexibility and power by employing many of your tools and techniques as a Systems Engineer who spends a lot of time in this OS. Thank you!
Allen also posted a review of WFA 2/e on Amazon. Thanks, Allen, for your words, and for feeling led to reach out and share your thoughts, not just with me, but with others!
I just wanted to tell you how impressed I am with how thoroughly you cover the methods covered in your book. Usually when I pick up a book like this I’m prepared for more questions than when I started but that’s not the case with Windows Forensic Analysis. It’s elegantly worded and easy to follow which is hard to find when it comes to technical books. I read for about 8 hours straight yesterday on a trip back from the east coast and I still didn’t want to put it down. As a long time Windows user, you’ve helped fill in a lot of blanks and I feel like I’ll have a lot more flexibility and power by employing many of your tools and techniques as a Systems Engineer who spends a lot of time in this OS. Thank you!
Allen also posted a review of WFA 2/e on Amazon. Thanks, Allen, for your words, and for feeling led to reach out and share your thoughts, not just with me, but with others!
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