Mounting a DD image

One of the things I mentioned in my new book was an alternative analysis method for performing computer forensic analysis. I specifically mentioned the use of Mount Image Pro for mounting a dd image as a read-only file structure, which opens up some areas of analysis that many may benefit from using. For example, during an intrusion case, one thing you may want to do is scan the image with AV software. This may save you a great deal of time trying to locate hacker tools by hand. Also, this is something you may want to do when you may be faced with the "Trojan Defense".

Another thought/useful option is this - we all have things that we look for everytime we open an acquired image of a Windows system, and there are other things that we look for on a case-by-case basis. Most often we do this through our forensic analysis software package, such as ProDiscover or EnCase. However, even though these packages ship with scripts to do some initial data collection and parsing for us, sometimes, they aren't as complete as they could be, or we'd like them to be, and it takes forever to get scripts updated because the few folks that actually write their own scripts are busy with other things. Sometimes you may be in a rush or under pressure, and may forget something that you would normally look for. So what if we had a script or a tool that would run through an image, pulling things out for us each time...all automated so that we wouldn't have to remember all of the different places could look, but at the same time, its all documented? Say, the tool would check to see if the Recycle Bin had been disabled, and then move on to parsing the INFO2 file for one user, or all users. Or, the tool would collect the audit policy from the system, check the Registry entries for the Event Logs, and then collect statistics from the Event Log files themselves, or automatically parse the Event Log files to .csv format (or both). Would that be useful?

Another use of something like this is for forensic analysis training. Mounting the image as a drive letter lets you dig into aspects of forensic analysis that while accessible via commercial forensic analysis applications, may be somewhat easier to grasp and work with, particularly for new students, or junior members of an IR/CF team or CSIRT.

Okay, so now, how do we do this? How do we start with just a dd image, and get to a read-only drive letter (ie., F:\, G:\) so that we can point an AV scanner or some other tool at it?

To get the dd image to begin with, you can use ProDiscover, Helix, straight dd, or even FTK Imager Lite. If you're using ProDiscover, you can use the Tools -> Image Conversion Tools -> VMWare Support for DD Images... option to create the necessary .vmdk file.

Another option for creating the .vmdk file is to use LiveView. Point LiveView at the dd image, choose "Generate Config Only" in the GUI (maybe even designate the OS rather than having LiveView guess it) and you'll end up with several files, to include two .vmdk files and a snapshot. LiveView makes use of the VMWare DiskMount utility (don't forget the free VMPlayer), and even though this does not mount the image as a read-only file structure, you can set the read attribute on the image file itself (attrib +r imagefile) as a precaution. Use the vmware-mount.exe to mount the snapshot (imagefile-000001.vmdk)and all of the writes will end up in the snapshot.

Another option is to look at FileDisk. From the screenshot, FileDisk appears to have a read-only (/ro) option. I haven't tried this one yet...installation requires a reboot for the driver to be installed. However, FileDisk will also let you mount ISOs as CDs using the "/cd" switch.

Once you have your .vmdk file, take a look at VDK and VDKWin (scroll down to VDKWin). VDK gives you the .exe and .sys file for mounting image files as read-only file structures (according to the credits, VDK owes a great deal to FileDisk), and VDKWin gives you a GUI for managing it all. A nice thing I noticed about VDKWin is that it's simply a GUI for managing all of the command line switches in VDK. For example, let's say you image a Dell system that wasn't reformatted before being installed, and it has one of those Dell maintenance partitions at the beginning of the physical drive. VDK lets you list available partitions, and then select the one you want to mount. Rememer, when you grab VDKWin, don't forget to also get the core files from the top of the page.

I did test this out using a sample image. I started with the ProDiscover solution, and launched the .vmdk file via VDKWin with no problems. I tried LiveView, and though the DiskMount (vmware-mount.exe) approach worked fine, VDKWin balked at an "unknown extent type". The extent description section of the LiveView .vmdk file had two lines...simply deleting the second one caused VDKWin to hang. So, I removed the second line, and added the size entry to the first line, in essence replicating what I found in the .vmdk file produced by ProDiscover, and then everything worked just fine.

One caveat: I already have VMWare installed on my system...I read in a Google News post somewhere that in order to use some of these tools, you may need to have VMPlayer or one of the VMWare products installed, as the tools may use some of the DLLs. Just be aware of this if this is an avenue you're going to take.

So, what we're left with is a Windows-based solution, using freeware tools, to obtain an image, and then mount that image as a read-only file structure, for analysis. Many of the tools on the DVD that comes with my book, such as SAMParse, are designed to be run against raw Registry files and are perfect for use with this methodology. Sweet!

Addendum: I have an image that was created using FTK Imager Lite, broken into 2GB chunks. I opened the image in ProDiscover using the PDS file format, and started my analysis. Last night, I used the ProDiscover capability for creating .vmdk files ("VMWare support for DD images...") to create the .vmdk file by pointing the tool at the .pds file. Then, I installed VDK and VDKWin, but not any of the other VMWare tools. After setting the read-only bit on all of the image files (attrib +h), I ran VDKWin and successfully mounted the image as the K:\ drive, in read-only mode.

Even though I use a fully licensed version of ProDiscover IR, ProDiscover Basic is free (as in beer) and includes the ability to create the .vmdk files.

Why current IR models don't work

A while ago, a buddy of mine was on travel, leaving his family at home. He called home from the airport whilst awaiting a flight and got some interesting news. He'd winterized their house several months earlier, which included shutting off the hose bibs from inside the house and purging the water from the pipes so they didn't freeze and burst. Well, about 36 hours prior to his call, there had been a need to run water from the faucet on the back of the house, so his wife had turned the hose bib on. However, being unfamiliar with all of the pipes and everything running through the closet, she'd also accidently turned off the gas to the house, which caused all of the pilot lights (on the gas range, in the gas fireplaces, and for the water heater) to go out. Listening to this, my friend started asking questions of his wife, many of which were answered "I don't know".

Listening to him tell this story, it became clear what his concerns were, but I wanted to hear it from him. While his wife was saying, "honey, you're going to come home from a long flight with several stops, layovers, and delays and not have any hot water to shower...sorry", he was hearing that there were possibly places in the house where gas could be seeping into the house. Thankfully, the gas used in homes smells, so it can be detected, but if the source is in an enclosed room...you see where I'm going with this.

I thought about this for a bit while I was running the other day, and it occurred to me that this almost exactly mirrors current incident response models. I know, I know...bear with me here. Consider the wife in this story to be the CEO (hey, don't we all???), and my friend his a CISO or security admin. The kids and pets are the staff. In this case, we have an "incident"...the gas coming into the house was shut off long enough to cause the pilot lights to go out. The CEO, based on her sphere of perception, understands the issue to be one of inconvenience...lack of hot water means no hot shower. She feels that they can wait until my buddy gets home to deal with it. However, my friend sees an even bigger "threat"...not only to property (ie, his house) but more importantly, to the health and safety of his family (corporate officers failing to accurately identify critical assets).

In response to this, my friend decided to embark on a training and educational approach to changing the "corporate culture" of his family to be even more cognizant of the issues and potential impacts of such incidents. In part, this is where the story takes a turn and ends differently from what happens in business (corporate, government, etc.) organizations today.

So how does all this apply to these business organizations? Look around...or look here. It's quite a long list, but see any duplicates, either in what reportedly occurred, or in the name of the organization?

So, how do we fix this, you ask? Glad you asked!! Apparently, security overall (and not just IR) is something that is not part of the "corporate culture" of many organizations. Responding to incidents often times gets me nothing but blank stares when I ask questions about the status of systems, where systems are "located" in relation to each other, etc. That's nothing unusual.

Speaking of "corporate culture", when I was in the Marine Corps, we had a corporate culture, one that was easy to remember - "every Marine a rifleman." Basically, what that meant was that every single Marine, officer or enlisted, must be qualified in care, feeding, and effective and deadly use of the M-16 rifle. Every Marine received training in its use, and had to go through annual requalification. The same was true for officers...up through the rank of Captain, every officer had to qualify annually with the M-16 as well as their own TO weapon, the M-9. But this wasn't all we did...this was part of the many things we did, but it was part of our corporate culture. I believe this served us well in many incidents, particular in Iraq, where the "front lines" were often right in front of you, and it didn't matter if you were an infantry Marine or a cook or a Motor T driver.

My point is that we can talk about IR all day long, but things won't change unless someone with the ability to change the corporate culture does so. Everyone, particularly the IT staff, needs to be more security conscious, and be more familiar with the assets their protecting. What are the critical assets of the company, as defined by the CEO? How does an IT admin's job of maintaining servers and systems relate to accomlishing the mission of protecting those assets?

Also, consider this...in the military, everyone's trained in "immediate actions". If an M-16 jams, every Marine knows the immediate actions to perform to get that weapon back into service. Marines on patrol know that if caught in a near ambush, then the response is to attack the source of the ambush, immediately and with maximum violence. Consider this...why can't the IT staff be trained in "immediate actions", as well? If unusual traffic is seen on the network or anomolous behavior appears on a system, there are things that the IT staff can do immediately to identify the issue. There are other things that they can do in order to quickly address the situation.

It all starts with a top-down approach to the corporate culture. From there, IT staffs need to receive training...functional, hands-on training that applies to the systems they work with every day. Going away to Linux-centric training for someone in an all- or predominantly-Windows shop is a waste of time and money. There needs to be core, central set of knowledge and training that every IT staff member receives and is responsible for knowing...in the Marines, every officer, be they a pilot, a communicator, or a supply officer, goes through the same training at The Basic School. From there, certain members of the IT staff should receive specific training based on their areas of responsibility, be they routers, firewalls, servers, applications, etc. They need to understand these areas and systems inside-out, in much the same way a Marine can field strip, clean, and reassemble the M-16.

So, if you're reading all this and you're not someone in the IR business, you're probably thinking, "oh, he's just saying this so that he can get our money." No, I'm saying this so that you don't loose my data...my SSN, my credit card number, etc. Or my wife's. Or, several years from now, my daughter's or my niece's and nephew's. We see it in the media all the time, with these high profile "hacks" involving someone breaking in and stealing data, or sensitive personal information being lost. Or critical applications and systems being taken over, compromised, and p0wned. These incidents are no longer the result of joy riders on the Information Superhighway...that ended a while ago. There is a profit motive behind this...these crimes are being committed because there is money involved. There needs to be a shift in the corporate culture such that this data is better protected, and when something does happen, the response is something more than paralysis. What would you do if you had a fire in your home? Would you evacuate your family, and if the fire were small and isolated enough, would you attempt to put it out? Would you call the fire department? Dumb questions, I know...but when incidents are occurring today, many corporate cultures make it okay to ignore the situation and simply go back to sleep. Worse, the situation is recognized as something unusual, but everyone is paralyzed, and the fire department gets called only after the house has burned down.

Thoughts?

Thoughts on Incident Response/Management

Others have recently posted their thoughts on incidents and incident response (1, 2), and since this is an IR blog, of sorts, I thought I'd throw my hat into the ring, as well.

I don't really have a list of thoughts on IR, per se...its more a case of one thought from which all others spring. Basically, that is that organizations really need to start taking a proactive approach to Incident Response and Incident Management.

Incidents are going to happen. We can take that as a given. The days of joy-riding on the Information Superhighway are about over...there's simply too strong a profit motive these days. Why get a copy of BO2K onto a system and open and close the user's "cup holder", when you can quietly collect the contents of Protected Storage, capture keystrokes as the user logs into his online banking site, etc.

So what do you do? Well, first off, senior management needs to take this "security thing" seriously and treat it like a business process, not an ad hoc thing that you scramble to implement when you need it, and then drop it (cut the budget) when you don't. Walk around headquarters one day and look at the finance department...or marketing...or Ops. HR. All of these are business processes that you need to run a successful company. But how did you know that? Did someone tell you? Or did you suddenly see the need? Either way, people have been saying for years that you need to have security, and if you don't recognize the need simply by reading the paper everyday...

At some point, someone's going to throw up their hands, throw a huge budget at security, hire a bunch of (the wrong) people, and then proclaim security a failure. It doesn't work! Sound familiar? Is that how you would run your Finance Department? How about Payroll?

This security thing is really simple. Start by looking at your assets...what are you trying to protect? Is it sensitive personal data (a la CA SB1386)? Are we talking about critical systems, applications, or data...or some combination?

Once you've identified the assets, look at the threats. But keep in mind that this is no longer seige warfare, where you watch in wonder while barbarians pound at your gates...or your firewall. We're well into what the United States Marine Corps refers to as "manuever warfare". We're facing a battle with no defined front lines; ingress points include web browsers, rogue WAPs, etc. Have an assessment done, and if the result is "pay us a ton of money to fix it", then you may need to ask for your money back! In all infrastructures, there are things that can be done that don't cost money, but do have an inherent cost...things like cultural and political changes, changes in how you do things (ie, communal Admin/root accounts, etc.).

Train your people and hold them accountable. You're not going to hire an IR staff and keep them in a room with "break glass in case of emergency" written on the door. However, a great deal can be accomplished by training your current staff in how to manage and respond to incidents. Designate some personnel as incident responders, with a suitable manager, and get them some training. Even if they are familiar with handling some incidents, the best training is functional and hands-on. Have regular refresher training in the form of incident response exercises...maybe even coordinate that with an unannounced pen test.

In fact, here's a great way to go about the whole thing. Get your folks the training they need to be tier 1 incident responders. This means that there are come tasks that they'll be able to handle, like EMTs. Then, seek out a professional response firm, and keep them on retainer so that they're available should you call, and then can be on-scene and paid on a per-incident basis. This kind of approach has is a win-win, particularly if the professional responders are the ones who are training and working with your team...they get to know and trust each other, and there's a great deal of knowledge transfer that goes on.

Where this kind of thing breaks down is when the responders are held accountable for something, and senior management isn't. Security (in general) and incident response are business processes, folks, and need to be thought of and treated that way.

BTW, one of the links in the first line of this post is to a fairly new blog: ForensicIR. Welcome aboard!

Forensic Challenges

Whenever something new comes out, one of the things people in particular fields ask is, how will this affect us and what we do? This is especially true in our field. With the recent release of new technologies, not the least of which is Vista, lots of folks have been asking about the challenges to digital forensics these new technologies will pose.

Thinking about this, I would suggest that the challenges don't come from "new" technologies being introduced, but rather from our community's myopic point of view.

I know what you're thinking...what did he just say? Well, I'm suggesting that new technologies...increased storage capacities, increased sophistication in cybercrime, new operating systems, etc...aren't imposing the "challenges" we think they are...we are. As a community, we're limiting ourselves, and imposing these challenges on ourselves somewhat artificially.

Rather than trying to describe my reasoning, let's look at a couple of examples. First, increased storage capacity...newer, smaller hard drives with greater capacity make things like iPods and cell phones that do everything for you possible. However, this is something that the forensic community has been dealing with for some time. This is not a 'new' challenge at all. The same holds true with new technologies, like Vista. New operating systems have been coming out all the time...at one time, Windows NT 4.0 was "new" (heck, even I remember that!).

What about drive encryption? Is this particularly a "new" challenge? Encryption has been around for a while, and we have to deal with encrypted files all the time. With freeware encryption for files, and even commercial products, it's not unusual to have to deal with such things. Those of us that haven't had to deal with such things specifically need to keep some knowledge of what to do, an "SOP", if you will, in mind in case we do encounter these things.

IMHO, the real challenges to the digital forensic community are largely self-imposed. New technology doesn't necessarily impose new challenges on the community, as the introduction of "new" technologies is almost a steady-state in this industry, isn't it? DOS led to Windows 3.1 and OS/2, which led to Windows 95 and NT 3.51/4.0, etc., etc. Storage capacity has increased over time. New devices have been introduced. There's really no "challenge" in this, per se...simply wait until someone produces a product to deal with the "new" technology, and things continue as before.

It appears that the real challenge is incorporating new ways of doing things, such as live response. Now, we won't always have the opportunity to employ live response, as not all of us have the benefit of talking to the "victim" prior to them taking some action on the affected system(s), but live response is one of those things that flies in the face of the traditional (dare I say "purist") approach to computer/digital forensics. However, live response can do a great deal to help us solve some of the other perceived challenges, if we can change the mindsets of the major players in the community. From there, this mindset change will permeate the minds of others...corporate IT, lawyers, etc.

What challenges do you see?

Getting service information during IR

During his BlackHat DC presentation last week, Kevin Mandia said that the persistence method used by many malware authors seems to have shifted to Windows Services. During the presentation, he mentioned using psservice.exe from MS/SysInternals to get information about the services on a system, and said that psservice.exe doesn't show the executable image used by the service, and that you'd have to get that information from the Registry.

Well, maybe not. Kevin's a really bright guy, and very busy. There are ways to get the executable image path...using WMI for example. Writing a quick Perl script (and then compiling using Perl2Exe so that it can be used easily with the FRUC/FSP), one can get the following:

Name : wltrysvc
Display : Dell Wireless WLAN Tray Service
Start : LocalSystem
Desc : Provides automatic configuration for the 802.11 adapter using the Broadcom supplicant.
PID : 716
Path : C:\WINDOWS\System32\WLTRYSVC.EXE C:\WINDOWS\System32\bcmwltry.exe
Mode : Auto
State : Running
Status : OK
Type : Own Process

Pretty cool, eh? Path the executable image, PID, start mode and state. Of course, CSV output is easier to parse...and yes, this program does come included on the DVD accompanying my book.

Book & Attending BlackHat DC

Recently, Troy Larson (bio and picture) graciously offered to review/tech edit my upcoming book, so to start, I asked the editor to send him two chapters; the one that covers volatile data collection and the one that covers Registry analysis. Here's a quote that I received from Troy regarding the Registry analysis chapter:

I really liked the registry chapter.  It is worth the price of the book alone.

Sweet! In the same email, Troy also mentioned that there wasn't as much info on Vista as there was on the other versions of Windows covered (2000, XP, 2003), but also said that this is largely due to the fact that there just isn't that much information available yet. secondedition

Speaking of the book, I found it on Amazon this morning, available for pre-order.

I spent most of yesterday at BlackHat DC and caught the first three presentations in the Forensics track...well most of them. I caught all of Kevin Mandia's presentation, as well as part of the presentation that followed on web app forensics, and then after lunch, I went to Nick Petroni and AAron Walter's presentation on VolaTools. Unfortunately, I didn't get to stay for the entire presentation.

Kevin's presentation was very interesting, addressing the need for live response. There were several comments that Kevin made, stating the need for "fast and light" response.

IMHO, there is a need for a greater understanding of live response...not just the technical aspects of it, but how those technical aspects can be applied to and affect the business infrastructure of an organization.

Following the presentation, I took a few minutes to jot down some notes and thoughts...I started by attempting to classify incidents (think of "Agent Smith" in The Matrix, classifying humans as a "virus") in terms of the speed of response required for each. I started by defining speed of response in general terms at first ("ASAP", etc.) and then attempting to become more specific but not to the point of minutes and seconds. Regardless of the angle I approached the problem from, the one thing that kept coming to mind were business requirements...what are the needs of the business? Sure, we've got all these great technical things we can do, and as Kevin pointed out (as did Nick and AAron), a lot of folks that he's talked to have said, "we've already got all this data (file system data, etc.) to analyze...we don't do live response because the last thing we need is more data!"

I guess the question this point is, is the data that you're currently collecting for analysis meeting your business needs? If you're backlogged 6 months in your analysis...probably not. Depending upon the nature (or class) of the incident and your business environment, it may/most likely will be useful to rapidly collect and analyze a specific subset of volatile data during live response so that you can get a better picture of the issue, and progress through your analysis more accurately and efficiently.

One of the things Kevin pointed out is that malware (can anyone verify that Kevin only said "malware" 6 times...I wasn't keeping track) is including the capability of modifying the MAC times of files written to the system. This is an anti-forensic technique that severely hampers those using the current "Nintendo forensics" approach to analysis.

I think that some people are beginning to recognize the need for live response and how it can be useful in an investigation. However, I think that the issue now is one of education...how do those currently doing response of any kind (live or otherwise) break out of their current mindset, and shift gears? By shifting to a more holistic approach and using live response where applicable, and in the appropriate manner, those people will begin to actually see how useful this activity can be.

The presentation I found to be the most interesting was Nick and AAron's "VolaTools" presentation. Once Nick finished with the overview (presenting some great information on why you'd want to use tools like this), AAron kicked off into the how portion of the talk. I think their approach is an excellent one, in that they've identified a major stumbling block for this kind of analysis...the tools that are available are not included with EnCase and are not "push the Find-All-Evidence button" kinds of tools, and people aren't using them because the tools themselves are too different. In a nutshell, there's a confidence factor that needs to be addressed. While Nick and AAron's tools are written in Python, they do provide a command-line interface in the Basic version of their tools that allow the user to extract information from a RAM dump in nearly the same manner as you would on a live system...to list the modules used, you would use a "dlllist" command (as opposed to listdlls.exe), and to list handles, you'd use "handles".

I can't wait to download and look at their tools...these two guys are really bright and have just moved the issue of Windows memory analysis forward a couple of huge leaps. And thanks to guys like Jesse Kornblum for things such as his Buffalo paper, because we can then use AAron and Nick's work as a basis for incorporating the pagefile into the memory analysis, as well.

Oh, and while I did meet both Ovie and Bret, unfortunately Ovie wasn't wearing his CyberSpeak t-shirt, so I guess I don't get to have a beer with Bret! ;-(

One final thing about BlackHat DC...seeing Jesse do his impression of a sardine was worth the price of admission! Speaking of Jesse, it looks like he's been busy on the ForensicWiki...

(In)Secure Magazine Mention

I received an email from Didier Stevens this morning, letting me know that he'd mentioned me in an article that he wrote for (In)Secure Magazine (issue 1.10, Feb 2007). His article, "ROT-13 is used in Windows? You're joking!" starts on pg 72 of the PDF, and runs through pg 77, where he mentions my ProScript.

Didier's article is on the use of ROT-13 to "encrypt" information that Windows uses to keep track of most frequently used programs (MFUPs). These MFUPs are tracked in order to populate the new Start menu, in both the pinned list (left side) as well as the most frequently used programs list (at the bottom)...see Didier's article for the full explanation.

The ProScript that Didier mentions is a Perl script (go figure, right??) that works with Technology Pathway's ProDiscover forensic analysis product, and parses the NTUSER.DAT files for all of the users on the system, extracting and "decrypting" the UserAssist entries and sorting them in order based on the timestamps that Didier mentions in his article. The ProScript is run against an image that is open in ProDiscover.

I also use a Perl script that parses the raw NTUSER.DAT files, and collects the same information...an excerpt of the output appears below:

G:\book2\DVD\ch4\code>pnu.pl d:\cases\ntuser.dat
LastWrite time = Mon Sep 26 23:33:06 2005 (UTC)
Mon Sep 26 23:33:06 2005 (UTC)
UEME_RUNPATH
UEME_RUNPATH:C:\WINDOWS\system32\notepad.exe
Mon Sep 26 23:26:43 2005 (UTC)
UEME_RUNPATH:Z:\WINNT\system32\sol.exe
Mon Sep 26 23:22:30 2005 (UTC)
UEME_UISCUT
UEME_RUNPATH:Downloads.lnk
Mon Sep 26 23:16:26 2005 (UTC)
UEME_RUNPATH:C:\Program Files\Morpheus\Morpheus.exe
Mon Sep 26 23:16:25 2005 (UTC)
UEME_RUNPATH:Morpheus.lnk
Mon Sep 26 23:15:04 2005 (UTC)
UEME_RUNPATH:C:\Program Files\Internet Explorer\iexplore.exe
Mon Sep 26 23:04:08 2005 (UTC)
UEME_RUNPATH:d:\bintext.exe

The UserAssist keys record user activities that are performed via the shell (ie, Windows Explorer). The UserAssist key actually has two subkeys, both of which are GUIDs or CLSIDs...one for the Active Desktop, and the other for the Internet Toolbar. If you've installed IE 7.0, you will see a third subkey.

Both the ProScript and the Perl script mentioned here will be available on the DVD that accompanies my next book, Windows Forensic Analysis, due our later this spring from Syngress/Elsevier.

Didier's got some other very interesting posts on his blog, so be sure to check it out when you get a chance.

BlackHat DC

Who's going to BlackHat DC? I found out today that my publisher has a pass available for me, and I'm looking forward to the opportunity to attend (hopefully, at least the first day of the briefings). It's been a while since I presented at BlackHat (2002, 2004), and the Forensic track looks like a good reason to go back!

Why I like Perl for Forensic Analysis

Many times when I post to a list or give a presentation and talk about using Perl, I almost immediately hear comments back such as, "I can't do that because I don't know Perl".

Well, I have to say, it's not about knowing Perl, or how to program, really. Most of the stuff I'm doing with Perl is translating binary stuff into something readable (timestamps, checking flag values), and just doing repetitive stuff. For example, in Windows Memory Analysis, I just use Perl to implement various processes that are repetitive and boring, and therefore I would be prone to making mistakes. The same is true with tools like SAMParse and SECParse that I use to parse the contents of raw Registry files. The information is there for anyone to see, extract, and interpret. I simply use Perl to do it automatically. In some cases, I write the scripts I do because there is commercial application that provides anywhere close to the information I want or need.

I have written tools to parse RAM dumps, parse Event Log .evt files (without using the Windows API), parse raw Registry files, etc. I wrote these tools because I needed them, and as it was very likely that I would need to do those things again, I automated the process in a Perl script.

I also hear things like, "I don't want to have to keep Perl up-to-date". I think in a lot of cases, comments like these come from folks who don't know a great deal about Perl...and you know...that's fine. It's okay, people. I'm not being a Perl snob or forensics snob or whatever snob, I simply use Perl to automate the repetitive tasks that make up my work day. Besides, I also use Perl2Exe, so all the tools that will be provided on the DVD that comes with my next book (Windows Forensic Analysis, from Syngress/Elsevier) will be provided with Perl "source" code, as well as a standalone EXE file that will allow you to run the tools on a Windows system without having to install Perl.

Perl is an interpretted language, so I don't have to "compile" my scripts to run them, and I can easily make modifications and changes to the scripts, updating or correcting them quickly. The scripts are somewhat self-documenting, although I do add my own comments to give myself a better view of what's going on, so I can figure out was I was doing a year or two later, rather than just look at it and think, "*I* wrote this??". Finally, Perl gives me a freedom and flexibility that is not available in commercial tools. For example, there are commercial tools that will allow you to view certain Registry data in a nice GUI, but you can only view that data, and only one entry at a time. With Perl, I can output multiple entries, as well as correlate data from multiple keys, such as when I want to show USB removable storage devices, any drive letters they were mapped to, and the last time each device was connected to the system (I should call this one "USBParse"). Don't like ASCII output in block format? In a few moments, I can have CSV style output. Ta-da!

So...some folks don't like to use Perl or open-source tools for forensic analysis, and that's okay. I use Perl because I know that if I have to perform some kind of analysis or correlation once, I'll probably have to do it again, and in order to avoid (as much as possible) forgetting a step or making a mistake, I'll automate the process.

Besides, I give most of this stuff away for free, as in beer.

Intentional erasure

An interesting question appeared on one of the listservs a bit ago..."what is an investigator's protocol for demonstrating intentional erasure of data, ostensibly done by the user to remove evidence from a system?" This is an interesting question and since it doesn't fit neatly into one of the FAQ sections at the end of a chapter in my next book, I thought I'd address that question here in the blog.

The first thing I would look at is the level of erasure that has occurred. One of the first places to check is the Recycle Bin. Many users delete files through the Explorer shell, and they end up in the Recycle Bin...from there, some users don't bother to empty the Recycle Bin. However, this does show an intentional attempt to remove data, based on the actions that are required to move the files to the Recycle Bin.

I have seen instances in which the user has deleted files (ie, sent to the Recycle Bin) and then emptied the Recycle Bin. In such cases, the last modification time on the INFO2 file in the Recycle Bin may give you an idea of when the Recycle Bin was emptied. Again, this may show intent.

In some cases, many of the sectors for the files were then overwritten due to the limited defrag that occurs about every 3 days on a Windows XP system, making the deleted files unrecoverable.

I would also suggest checking the contents of the UserAssist keys, and on XP systems, the Prefetch folder, to see if there are any artifacts to indicate that an erasure tool of some kind was used. This may range from commercial tools to freely available VBS scripts.

One important thing to keep in mind when performing forensic analysis is that given some artifacts, we can expect to see other other artifacts. For example, if we find that auditing of logons has been enabled, and we see user profiles with MAC times (on the NTUSER.DAT files, etc.) that indicate logons, then we can expect to see some information in the SAM file, as well as the Security Event Log. By correlating these sources, we can develop information about our case. However, the absence of those artifacts that we know we should see (but don't) is itself an artifact.

Scripts for parsing the Registry

I was working on a script recently to expand the reach of the Registry Analysis material in my upcoming book, and I thought it would be a good idea to implement something that would parse the audit policy from a system. So I wrote poladt.pl, a Perl script that uses the Parse::Win32Registry module to extract the necessary value from the raw Security file and parse it, displaying the audit policy as shown below:

G:\perl>poladt.pl d:\cases\security
LastWrite: Fri Sep 9 01:11:43 2005 (UTC)
Auditing was enabled.
There are 9 audit categories.

Privilege Use..............None
Object Access..............None
Account Logon Events.......Both
System Events..............Both
Policy Change..............Both
Logon Events...............Both
Account Management.........Both
Directory Service Access...None
Process Tracking...........None

Note: I added the little dots so that the output would line up better and be easier to read; formatting in the blog is a little beyond my current skillset.

Pretty neat, eh? You can compare this to the contents of the Event Logs (I still use the File::ReadEvt module that I wrote to do this, as the Event Viewer still reports the files as corrupted sometimes when you extract them from an image and try to import them into the Event Viewer on your analysis system). If I get any information about other values to parse out of the raw Security file, I'll add that to a script and call it "SECParse".

This script is will be found in the Bonus section of the DVD that comes with my book. Look for Windows Forensic Analysis from Syngress later this spring.

SAMParse

Not too long ago, I blogged about using the Parse::Win32Registry module to parse raw Registry files, specifically the SAM file.

Since then, I've added to the code a bit, so that not only does it retrieve user information, but group membership info, as well. In this way, it's similar to the ProDiscover ProScript I use to do the same thing, only SAMParse works on the raw Registry file, and can be used when exporting the SAM file from your image. It also works on the SAM files located in the Windows XP System Restore Points. It's a useful tool and requires some additional testing, but for the most part it does provide me with a view into a Windows system that I wouldn't otherwise have.

As a side note, I've also written a tool that parses the audit policy from the Security file, returning information similar to what you can view on a live system using auditpol.exe. When combined with other information from the Registry, this lets me know what I should expect to see in the Event Logs.

Both of these scripts, and others, are provided on the DVD that comes with my upcoming book, "Windows Forensic Analysis", due out from Syngress/Elsevier this spring. The scripts will be provided as Perl code, as well as standalone executables 'compiled' using Perl2Exe.

St Louis...here I come!

I'm headed to the DoD Cybercrime Conference in St. Lous, MO, next week. I'll be presenting at 0830 on Thursday morning. It turns out that there are a total of four presentations on Windows memory analysis at this conference. Wow. Had I known, I might have submitted on something else, like Registry analysis. The other presenters include Jesse Kornblum, Tom Goldsmith, and Tim Vidas. I'm sure that there will be some overlap, but I also think that this will be a very interesting conference.

Jesse was nice enough to set up a BoF/BYO on Memory Analysis on Thursday evening...swing by and say hi.

Addendum, 27 Jan: Okay, I'm back, safe and sound. I only regret that I did not get to spend as much time as I would have liked with the folks I met at the conference, but work called...

Legends of the Tech Industry

Okay, this post is not specific to Windows or IR, but I wanted to mention this...

Ever since I was in graduate school, I've been interested in the real stories behind the legends of the technology industry. Actually, it really goes back further than that to when I was in high school...my calculus teacher held Grace Hopper as her personal hero. Skip forward 10 years and I'm in grad school walking by Gary Kildall's former office every day.

I could keep rattling off names, but I wanted to share something that I had read yesterday...this online article from WSJ.com about John Draper, aka "Cap'n Crunch". I first saw the article linked from SlashDot just by chance, and I found the article itself to be fascinating. I happened to catch John on IM and he asked me for my opinion about the article. I told him what I thought, and by that time, he'd gotten started on his day so his thoughts were "mixed". Regardless of what the author of the article chose to point out and how he chose to protray John, I do think that it was a good thing that Steve Wozniak was quoted and that John's relationship with both "The Woz" and Steve Jobs was at least pointed out.

I think it's cool to be able to get the "inside scoop" as it were, to be able to pierce the veil of mystery (and misinformation) that is put up around people like John, Woz, etc., by the media. Whether it's an article, a book, or a movie, there's always something that was misinterpretted or simply done wrong to make the piece suitable for public consumption. Also, it's good to get another perspective on some of the events in history. Very cool.

Fundamentals

MS recently posted their Fundamental Computer Investigation Guide for Windows. You can download the document or read the entire doc online.

I haven't heard too many opinions yet about this document, good or bad. It may be because most folks aren't aware of it. I will say right up front that I was involved in the editing process, so I'll have a slightly different view. I've seen this document in various forms, and read each of those iterations at least twice.

The paper is intended for IT professionals in the United States who need a general understanding of computer investigations, including many of the procedures that can be used in such investigations and protocols for reporting incidents. Okay, that's a great way to start when writing a fundamentals paper. The paper seems to be directed at folks who either don't normally respond to incidents, or haven't done so before and are now in a position where they are required to do so.

The paper consists of five chapters and an appendix. I'm not going to go through each one, but rather just mention some highlights. I do think that the paper is worth the time to read it, as anyone who reads it is going to get something out of it, positive or negative.

Chapter 1: Assess the Situation: This chapter provides some good advice and things to think about when an incident occurs; I would suggest, however, that most of those things (obtain authorization, review laws, etc.) be done before an incident occurs...that way, attention can be focused on responding to the incident. The Conduct a Thorough Assessment section is fairly comprehensive, and as you read it, keep in mind that no one will be able to list everything you need to know for every incident. Not only do incidents vary, but the same worm on two different networks will be handled differently, because each infrastructure is different, both from a technical/network perspective and a human/socio-political perspective. I would say that there's enough there to get you started, and going forward, it's better to know or not know than to make things up; many an investigation has gone down the wrong path because someone made assumptions based on too little information.

One thing I would like to see changed about the paper is how data about an incident is referred to. In the Prepare for Evidence Acquisition section, the first sentence says in part, "To prepare for the Acquire the Data phase..." So which is it...evidence or data? Given that many states are considering PI laws, it is important to differentiate between the two. Also, consistency of terminology is just a good idea.

On a positive note, the first chapter ends by referring to documentation. Documentation is very important during an investigation. Let's say that you're sweeping across servers to identify a piece of malware...if you don't document your process (what's being checked and why), you're going to have folks who go to a server and don't know what they're supposed to do. Also, you need to document which systems have been scanned and by whom, so that you don't spend a great deal of time rescanning the same server over and over again. Remember, if you didn't document it, it didn't happen.

Chapter 2: Acquire the Data: This chapter glosses over data acquisition as part of incident response. There is a reference to the Tools section in the Appendix, but the tools listed are exclusively either SysInternals tools or native commands on the system. Don't get me wrong...there are some extremely useful tools from SysInternals, but what's missing is a description of what information needs to be collected, and the best tools for doing so. For example, when responding to an incident, the first things I want to know are:

1. The list of active processes, with the full path to the executable image and the command line to launch each one. I'd also like to know the user context of each process.
2. Network connections.
3. Process-to-port mappings, so that I know which network connection is owned or used by which process.
4. Who is logged into the system (NetBIOS, mapped shares, Terminal Services, etc.)
5. Running services.

This is just the basics...there's more info that I won't get into here (hey, I need something to blog about later, right?). It's not that the tools mentioned won't provide that information...some do. It's that the paper doesn't mention what's important to know...it just tells the reader that there are some tools they can use.

Chapter 3: Analyze the Data tells the reader what they should do with the data they've collected. In the section on analyzing host data, you'll see the following statement:

...you might use the Microsoft Windows® Sysinternals Strings tool to search the files located in the \Windows\Prefetch folder. This folder contains information such as when and where applications were launched.

Don't get me wrong...I agree with both sentences. I just don't think that the two of them should be next to each other. Why? Well, the information maintained in a .pf file regarding when the application was launched is a 64-bit FILETIME object...strings.exe won't find that for you. While using strings or BinText from FoundStone can be very useful when looking for ASCII, Unicode, or Resource strings within a file, neither will help you locate the FILETIME object.

There's more to it than that, though. When responding to an incident, how do you identify a "suspicious" file or process? Within your infrastructure, what constitutes suspicious? Some might think that running three or even four remote desktop applications is suspicous, while others may think that multiple copies of svchost.exe running on a system is suspicious.

At this point, I think that I've provided enough comments regarding what I saw to be good in the paper, as well as what, IMHO, could be improved of changed. I think that the paper is a good start, but don't expect to sit down and read it, and then be able to conduct an investigation. I still think that MS would be better off with a different structure to documents such as these, directing different versions to different audiences. For example, a high level document for incident managers, one that's a bit more technical for incident team leaders (so that they can evaluate the performance of the team members), and then separate documents for data acquisition and analysis for host- and network-based live acquisition, as well as acquiring an image.

Thoughts?

P0wned by certs

Have we been p0wned by certs?

You're probably asking yourself, "What the...?" right about now. Bear with me on this one. How many of us go away to training, receive a certification, and then never use that training again? Or worse, without an instructor there, we are sloppy about how we use the training, and then it's as if we had never gone in the first place. Come on, raise your hands. Okay, now, think about it...how many of us go away to training, come back, and thankfully never get evaluated on what we learned?

We've all seen it...we meet someone with a certification in, say for example, incident handling. And then we watch how they go about handling an incident, either in a training scenario or during a real incident, and we wonder...why are they doing that, or "what the...?"

I'm sure we could all trade stories on this, but I think that we've already gotten to the point. So the question becomes, what's the purpose of the certification if the person who gets it cannot then perform to the minimum level specified by that certification?

Back in the '90s, I decided that I wanted to learn SCUBA. So I went to the nearby military base, took classes, paid my tuition, took the "final" and then received my certification. From that point on, if I failed to perform at the level specified by my certification, I could have seriously injured (or killed) myself, or worse, others. Had I been unsafe and irresponsible, some one would have likely reported me, or at the very least, refused to dive with me and left me to hurt only myself.

The military itself is very similar. If you get sent off for training, it's very likely that when you return to your unit, you will have to actually use that training for something. During military training, I was taught how to disassemble and reassemble several weapons, to include the M9, M16 (w/ M203 40mm grenade launcher), M249, M60, and M2 .50 calibre machine gun. Not only did I have to pass a practical, but I then had to use that knowledge at my first unit to teach the same things to others.

So someone goes off to learn to be an incident handler and then returns to their organization, and an incident occurs. How is the certified individual evaluated, or are they evaluated at all? What is the outcome of the incident? Does the certified individual declare that the incident was the result of "rootkit" with no data to support that claim?

See, I guess what I'm getting at is...are certifications effective, or have we been p0wned by certs? I guess you really have to look at the purpose of a certification, and what it's intended for. However, I do have some recommendations as to an alternative approach...

1. Rather than sending someone off to take generic training, have functional training within your organization. That way, the training can be specific to your environment, and immediately useful in that environment. Be sure to coordinate with the instructor and provide input on the types of incidents you're seeing.
2. This type of training isn't just for the technical folks...managers need it, too. Not to the same technical detail, of course, but managers need to know what skills they are deploying against an incident, so that efforts can be coordinated and properly...uh...managed.
   
3. Managers also need to know how to evaluate the performance of the team, as well as each member. After all, don't we tend to remember things better if we know that we're going to be tested on it, and that something (bonus, promotion, etc.) may be riding on how well we use that knowledge? Also, being able to evaulate the team will allow the manager to identify shortcomings, obtain additional training, etc. One great way to do this is to see who's really strong in one area, and have them work with others to bring them up to speed.

So, in a nutshell, IMHO 'tis better to spring for functional training that can be used and evaluated than to send someone off for a certification and then not be able to evaluate them when they return. I do believe that certifications have their purpose, but I also believe that there a few folks out there that actually evaluate interview candidates or new hires or even those who've just received their certification.

Thoughts?

New SANS Cert

Do we need another SANS cert? I don't think it's so much about us...it's what SANS wants.

I was reading TaoSecurity this morning and ran across this link to the recent SANS newsletter...

Does anyone on your staff do an excellent job of cleaning out PCs that have been infected by spyware and other malicious software. We are just starting development of a new certification (and related training) for Certified Malware Removal Experts and we are looking for a council of 30 people who have done a lot of it to help vet the skills an dknowledge required for the certification exam and classes. Email cmre@sans.org if you have a lot of experience.

I looked at this and thought...hhmmm...why create a new certification for skillsets that admins should already have? After all, malware detection is really just an advanced form of troubleshooting...which all admins should be knowledgeable in, right? I mean, when you have trouble with your car, do you examine it (ie., look at the gas guage and determine you're out of gas) or do you just abandon your car on the side of the road and get a new one?

Of course, there is a school of thought that believes why should you certify someone to run "format c:\", then fdisk, then re-install the OS? Ugh. I don't know which is worse...thinking that "slash and burn" is an acceptable solution, or certifying something like this.

Thoughts?

IMHO

I received some questions from readers and I thought
that I'd take a crack at them...

With consumer and commerical hard drives getting larger
and larger (soon there will be a consumer-level 1TB HD)
what effect will the sheer volume of information have
on the forensics community in general, and the 
open-source forensics community in specific? Does the
future include more automated tools? Distributed forensic
examinations? Will the open-source forensic 
community be able to keep up with the commercial tools?

For the most part, this appears to be two separate
questions, but I'll treat them as pretty much the same
one.

This is nothing new...the challenge of increasing volumes
has affected the forenic community since...well...since
there was storage.  Capacities have always increased...such
is the nature of a consumer market.  So what's the answer?
Well, in a nutshell...the Age of Nintendo Forensics is
dead.  What I mean by that is that new techniques,
processes and methodologies need to be employed to
meet these challenges.  We can no longer rely on
simply pushing a button...we have to understand
what it is we're looking for, and where to
look for it.

Notice I didn't say "developed".  Rather, I said "employed".
Yes, it was my intention to imply that these techniques are
already available, and actually used by a number of
practioners.  However, the vast majority of the digital
forensics community appears to rely on the traditional
approach to computer forensics analysis, which can be
likened to killing the victim of a crime and performing
an autopsy to see what happened.

Live analysis techniques need to be employed more often.
Many traditionalists say that "I won't use these
techniques until they've been proved in court."
Well, consider this...at one point, computer forensics
wasn't used in court, and had to be proven.

Suffice to say, computing technology grows in complexity
...this applies to the hardware, as well as the software.
Accordingly, forensic techniques need to keep pace.
The traditional techniques are still usable...I'm not
saying that they aren't...but practitioners can no longer
learn one thing and hope to stay in business as complexity
and change surrounds them.  We need to grow in knowledge
and understanding in order to keep up.  This includes
Locard's Exchange Principle, as well as understanding
what actions or conditions lead to the creation and
modification of certain artifacts...from that, we
understand that the absence of an artifact is in
itself an artifact.

Some of the challenges introduced by Windows Vista
include extracting live memory and (presumably) an
increase in use of EFS by consumers. How can these 
challeges best be addressed by the forensics community?

The challenge of extracting live memory has been an
issue since Windows 2003 SP1, when user-mode access
to the \\.\PhysicalMemory object was restricted.
However, has it really been a challenge, per se?
How many folks have obtained memory dumps, and of
those, how have they been used?  It isn't as if
the vast majority of the community has been using
physical memory as a source of evidence and
presented that in court.

That being said, these challenges will be addressed
by a small portion of the forensics community. 
That core group (and it may be dispersed) have
developed processes and methodologies, as well as
documentation, that they will use, and even
publish.  However, it may be a while before the
rest of the "community" of forensic practitioners
catches on and begins using these on a regular
basis.

Since Vista was specifically asked about, I'll
throw this out there...there is a Registry value
called NtfsDisableLastAccessUpdate, and yes, it
does just exactly what as it sounds.  If this
value is set to "1", then the operating system
will not update last access times on files. 
From NT through 2003, this has been a setting
that was disabled by default, and recommended
to be set for high-volume file servers in order
to increase performance.  However, on Vista,
this functionality is enabled by default.  What
this means is that examiners are going to have
to use other techniques for determining timelines
of activity, etc., and that may even require
Registry analysis.

Do you think there are ethical challenges
specific to forensic examiners or 
incident handlers? What do you think is
the most effective method of oversight in 
small offices where there may only be one
examiner? Would you say that strong personal
ethics are more important than technical
skill for an examiner/incident handler?

I would suggest that ethics is not something
that is restricted to forensic examiners alone,
but just as important in all fields.  I think
that in any field, a wake-up call comes when
someone falls into that "who are you to
question me" trap and then gets caught. 
I also think that is an important evolution
and good for the community at large. 
In this kind of work it is important to
remain humble and to constantly keep checking
ourselves.  There's nothing wrong with going to
someone else and asking, hey, did I do enough
here, or is this telling me what I think it's
telling me?  Overall, I think that builds trust,
and strengthens the individuals.

Thoughts?  Comments?  Email me, or leave a comment...

What's New So Far in 2007

Less than a week into 2007, and there's already a bunch of new stuff out that is really useful and really cool.

First off, there's a new blog on the streets...uh, web. Check out Mark McKinnon's CFED-TTF blog. One post up (at the time of this writing) and he already has some good info on the drivetable.txt file in XP System Restore Points. Great start so far!

Next, I was doing my monthly check on the E-Evidence site, and I found some really good stuff. No, wait...I mean REALLY good stuff! Raphael Bousquet has an interesting presentation on forensic triage. I know that its a product pitch, but the information on the idea of doing a triage is interesting, and something that should be, at the very least, discussed.

Golden Richard has an interesting PPT available that discusses next-gen digital forensics, to include topics such as live forensics. In the PPT, Prof. Richard points out that evidence (and he uses the term "evidence") exists in places other than those thought of in the "traditional" sense of forensics. He also talks about all the work that needs to be done...and while I agree, the question is, who will do that work? We do have a plethora (like that? No, I didn't get a thesaurus for Christmas) of students now that many universities and even community colleges here in the US have started offering courses and degrees in digital and computer forensics, but how long will it be before the big-brain ideas become something useable by investigators and examiners?

There are other presentations and papers available in this month's "What's New", but IMHO, the best paper availabe in this collection of links is Jessica Reust's paper on AIM trace evidence. What struck me most about her paper is that by the time I finished it, I actually had something useful, something I could use in an examination.

Now, on the flip side of all this, we should take it upon ourselves, as a community, to identify those things that we need, and either create them or put them on the table. What am I talking about? If you see a need or have a question, get it out there. Let someone know. Maybe someone out there already has the information you need, or is working on it.

Thoughts? Ideas? Comments?

New Year's Resolutions

I read today that there are some technical bloggers that have resolved to not make any New Years resolutions. Uh...okay...but isn't saying that you're not going to do that, in essence, a resolution? Hey, I'm just sayin'...

To kick 2007 off, I'm going to resolve to think big thoughts about IR and CF this year. Seriously. There has to be more to IR and forensic analysis than just what we're seeing. Think about it. There's got to be ton of evidence in Registry, right? After all, no one goes there. What about in RAM? And I know that there are a lot of questions out there, as I see some of them again and again. Questions like:

• How do I show files were copied to/from a system?
• How do I show that a CD/DVD was created on a system, and by whom?
• How do I show that a user account was changed from a User to an Administrator, and when?
  

What I would ask of all of you for 2007 is to build the knowledge base of the forensic community. Remember, it takes a village...I know, I can't believe I said that either, but hey, it makes my point. I've heard that a lot of folks don't post or comment or ask questions online because they don't want to look stupid. Okay, so post under someone else's name so they look stupid. Or post anonymously. Whatever works. The point is that there're a bunch of us out there working in this area, and every now and then a "hey, what about..." or "hey, what if..." or "hey, look what I found..." would really go a long way toward adding to all of our knowledge.

I've also been told that LEOs don't like to post questions because opposing counsel might see it and hold that against them in court. Well, if that's the case, then couldn't opposing counsel pretty much get any testimony thrown out because at one point, before all of your training and reading, you didn't know anything? I mean, doesn't it make sense that you'd ask, get an answer, and verify it, and let that be the case, rather than go into court with less of a case, all because you didn't want to ask a question?

One last thing...please resolve that in 2007, when posting questions, you'll include the OS and version. Seriously. I know some of you think that when someone responds to your post with "what OS/version?", you've been "chastized" or p0wned...whatever. Get over it. Most times, the answer will be different, depending on whether we're talking Windows 2000, XPSP2, or Vista, and I don't have the time to write or read an if...then...else encyclopedic answer.

Tagged!

Okay, I haven't blogged in a while...not because I haven't wanted to, but because I've been working (you know, that thing that pays the bills) and writing my next book (I've been exchanging chapters with tech editors). In between all that, I've been coding...and if I take this any further, I'm going to have to add a "really bad excuse" label to my blog.

So what exactly is a "blog tag"? To be honest, I have no idea. I first saw mention of it over on MySpace, so that should give you some indication of what it is. Now it's been picked up in the rest of the virtual world, even by nerds ("hey, I resemble that remark!") like us. So, my understanding from Richard is that I'm supposed to document 5 things people may not know about me, and then "tag" five other bloggers. Okay, here goes...

1. I attended the Virginia Military Institute for my undergraduate degree...by accident. I am a Navy brat, and was working toward an appointment to one of the federal service academies, and a high school counselor handed me an application to a small military school in the Shenandoah Valley. In fact, he gave me the last application in his folder, and didn't ask me to make copies of it. That's one of the things about my life that I would NOT change if I could.

2. While attending VMI, I ran marathons my senior year. Yes, looking at me, you'd never know that...according to many fellow Marines, I was "built like a brick sh*t house"...a physique not necessarily associated with nor conducive to marathoning-like activities. I first ran the Marine Corps Marathon in '88, with a finishing time of 2:57. This qualified me for the Boston Marathon, which I signed up for (that is, paid money) and ran...with a finishing time of 3:11. There's more to that story, but unless you attended VMI, it would neither make sense nor be funny. I ran that Marine Corps Marathon again in '89, while I was in The Basic School, and finished in 2:54. I still have all of my finisher medals.

3. In my first tour in the Fleet, I was in Okinawa for a year, stationed with MACS-4. This is the same sort of unit that Lee Harvey Oswald served in. I was a Communications Officer (MOS: 2502). While there, I studied Shorin Ryu, an Okinawan martial art. I'd like to study Akido and Krav Maga.

4. I have a horse, and yes, I ride. Western. Well, not so much "ride" in the traditional sense, like dressage, but more in the sense of "don't dump me off and I'll give you a carrot". I've even done this at a dude ranch, but the carrot thing didn't work.

5. I completed my master's degree at the Naval Postgraduate School, just prior to separating from the military. While there, I wasn't actively engaged in a whole lot (set up a 10Base2 network and connected the detachment to the token ring CAN), so I worked out quite a bit. At one point, I was doing 27 dead-hang, palms-facing-out pullups and ran the 3 mile PFT run in 17 minutes or less. I could bench press 360 lbs unassisted...and yet I was 5 lbs over the weight that the Marine Corps said I should be for my height. So I was placed on weight control, along with the Ho-ho and Twinkie bandits.

Now, on to the tagging...

Jesse Kornblum

Marcus Ranum

Dave Roth

Andreas Schuster

Robert "van" Hensing

Live long and prosper!

Artifact classes

I've been doing some thinking about IR and CF artifacts over the past couple of weeks, and wanted to share my thoughts on something that may be of use, particularly if its developed a bit...

When approaching many things in life, particularly a case I'm investigating, I tend to classify things (image the scene in the Matrix where Agent Smith has Morpheus captive, and tells him that he's classified the human species as a virus*) based on information I've received...incident reports, interviews with the client, etc. By classify, I mean categorizing the incident in my mind...web page defacement, intrusion/compromise, inappropriate use, etc. To some extent, I think we all do this...and the outcome of this is that we tend to look for artifacts that support this classification. If I don't find these artifacts, or the artifacts that I do find do not support my initial classification, then I modify my classification.

A by-product of this is that if I've classified a case as, say, an intrusion, I'm not necessarily going to be looking for something else, such as illicit images, particularly if it hasn't been requested by the client. Doing so would consume more time, and when you're working for a client, you need to optimize your time to meet their needs. After all, they're paying for your time.

Now, what got me thinking is that many time in the public lists (and some that require membership) I'll see questions or comments that indicate that the analyst really isn't all that familiar with either the operating system in the image, or the nature of the incident they're investigating, or both. This is also true (perhaps more so) during incident response activities...not understanding the nature of an issue (intrusion, malware infection, DoS attack, etc.) can many times leave the responder either pursuing the wrong things, or suffering from simple paralysis and not knowing where to begin.

So, understanding how we classify things in our minds can lead us to classifying events and incidents, as well as classifying artifacts, and ultimately mapping between the two. This then helps us decide upon the appropriate course of action, during both live response (ie, an active attack) and post-mortem activities.

My question to the community is this...even given the variables involved (OS, file system, etc.), is there any benefit to developing a framework for classification, to include artifacts, to provide (at the very least) a roadmap for investigating cases?

Addendum, 30 Nov: Based on an exchange going on over on FFN, I'm starting to see some thought being put into this, and it's helping me gel (albiet not crystalize, yet) up my thinking, as well. Look at it this way...doctors have a process that they go through to diagnose patients. There are things that occur every time you show up at the doctor's office (height, weight, temperature, blood pressure), and there are those things that the doctor does to diagnose your particular "issue du jour". Decisions are made based on the info the doctor receives from the patient, and courses of action are decided. The doctor will listen to the patient, but also observe the patient's reaction to certain stimuli...because sometimes patients lie, or the doctor may be asking the wrong question.

Continuing with the medical analogy, sometimes it's a doctor that responds, sometimes a nurse or an EMT. Either way, they've all had training, and they all have knowledge of the human body...enough to know what can possibly be wrong and how to react.

Someone suggested that this may not be the right framework to establish...IMHO, at least it's something. Right now we have nothing. Oh, and I get to be Dr. House. ;-)

*It's funny that I should say that...I was interviewed on 15 May 1989 regarding the issue of women at VMI, and I said that they would initially be treated like a virus.

MS AntiMalware Team paper

I know I'm a little behind on this one, but I saw this morning that back in June, the MS AntiMalware team released an MSRT white paper entitled "Windows Malicious Software Removal Tool: Progress Made, Trends Observed".

I've seen some writeups and overviews of the content, particularly at the SANS ISC. Some very interesting statistics have been pulled from the data collected, and as always, I view this sort of thing with a skeptical eye. From the overview:

This report provides an in-depth perspective of the malware landscape based on the data collected by the MSRT...

It's always good for the author to set the reader's expectations. What this tells me is that we're only looking at data provided by the MS tool.

Here are a couple of statements from the overview that I found intersting:

Backdoor Trojans, which can enable an attacker to control an infected computer and steal confidential information, are a significant and tangible threat to Windows users.

Yes. Very much so. If a botmaster can send a single command to a channel and receive the Protected Storage data from thousands (or tens of thousands) of systems, this would represent a clear and present danger (gotta get the Tom Clancy reference in there!).

Rootkits...are a potential emerging threat but have not yet reached widespread prevalence.

I don't know if I'd call rootkits a "potential" or "emerging" threat. Yes, rootkits have been around for quite a while, since Greg Hoglund started releasing them with the NTRootkit v.0.40. In fact, commercial companies like Sony have even seen the usefulness of such things. It's also widely known that there are rootkits-for-hire, as well. Well, I guess what it comes down to is how you define "widespread". We'll see how this goes...I have a sneaking suspicion that since it's easy enough to hide something in plain sight, why not do so? That way, an admin can run all the rootkit detection tools they want and never find a thing.

Social engineering attacks represent a significant source of malware infections. Worms that spread through email, peer-to-peer networks, and instant messaging clients account for 35% of the computers cleaned by the tool.

I can't say I'm surprised, really.

These reports are interesting and provide a different view of the malware landscape that many of us might not see on a regular basis...it's kind of hard to see the forest for the trees when you're face down in the mud, so to speak.

Even so, what I don't think we see enough of in the IR and computer forensics community is something along the same lines but geared toward information that is important to us, such as forensic artifacts. For example, how do different tools stack up against various rootkits and other malware, and what are the artifacts left by those tools?

Most of the A/V vendors note the various changes made when malware is installed on a system, but sometimes it isn't complete, and other times isn't correct (remember the MUICache issue??).

What would be useful is a repository, or even various sites, that could provide similar information but more geared toward forensic analysts.

Some sites of note

I've been perusing a couple of new sites that I've run across over the past couple of weeks and wanted to pass them on to others, and include some of my thoughts/experiences with the sites...

MultiMediaForensics - At first, this looks like another forum site, similar to ForensicFocus. One of the aspects of this site, however, is that the author maintains the shownotes for the CyberSpeak podcast. One of the most important things about this site is that it provides a forum for members of the computer forensics community to come together. In my experience, this is one of the things missing from the community...a "community". While ForensicFocus is UK-based, MultiMediaForensics appears to be more US-based, and that may have an effect on its popularity here in the US. If you follow the CyberSpeak podcast, or are just interested in computer forensics, make a point of contributing (post, write an article, provide a link, ask a question, etc.) to this site.

Hype-Free - While not specifically related to security or forensics, this site does have some interesting commentary. The author says in the "About" section that the goal of the blog is to "demystify security", so keep your eye out for some good stuff coming down the road.

MS AntiMalware Blog - Don't go to this site expecting to see MS's version of Symantec or some other A/V vendor that posts writeups on malware. However, you may find some interesting white papers and posts that will help you understand issues surrounding malware a bit better. For example, the ISC recently mentioned some highlights from one such white paper.

A little programming fun, etc.

I was working on writing my book yesterday afternoon (for those of you who live in my area and know how nice it was outside, I know...shame on me for being inside), and was working on a section that has to do with the Windows Recycle Bin. Most forensic analysts are likely familiar with the Recycle Bin and how it works, as well as with Keith Jones's excellent description of the Recycle Bin records (1, 2), so this is more than likely nothing new.

For the book, I wanted to throw together a little script that can be used to parse the INFO2 file, in order to illustrate some concepts that I am trying to convey in section. To my surprise, it was easier than I thought...I got something put together that works amazingly well - my only stumbling block at this point is how to present the data in such a way as to be useful to widest range of folks.

This just shows how useful a little bit of programming skill can be. Something I've been thinking about adding to my list of ProDiscover ProScripts is a script that will go through the Recycler directory and look for files that are out of place...not only files that are in the Recycler directory itself, but those that are in the user's deleted files but not listed in the INFO2 file.

Way Too Funny
Okay, now this is just way too funny...I was doing a search on Amazon to see if my next book is up for early order yet (my publisher said that it would be soon), and I ran across my master's thesis! If you're suffering from insomnia, it's well worth the price to grab a copy of this thesis...I used video teleconferencing traffic to verify the fractal nature of ethernet traffic, so that real statistical models could be used (rather than assumed) for constructing buffers on switches at the edge of ATM clouds.

Anyway, this was really "back in the day" (re: 1996). I was using Java (which, with the help of O'Reilly, I had taught myself) to write an SNMP application to poll Cisco routers for traffic data. I then used MatLab to perform statistical analysis tests of the data to determine its "burstiness" and verify its fractal nature. The video conferencing came in because it allowed me to generate data...I could sit in front of one camera, across the room from the other camera, and have measurable traffic generated across the network. At the time, Notepad was my Java IDE...this was before IBM's Java IDE came out (I saw my first copy of the IBM Java IDE at the end of July, 1997).

Something new from ISC
There were a couple of items I found interesting on the SANS Internet Storm Center handler's diary recently.

One was this item about malware that uses a commercial tool to detect the existence of a virtual machine. Very interesting.

Another is this writeup on the FreeVideo Player Trojan, submitted by Brian Eckman (the writeup also appears on SecGeeks and First.org, among other locations). Brian's writeup is thorough and very comprehensive...I like seeing this sort of thing posted, as it's a nice break to see a submission like this. Brian put a lot of work into the writeup, and looked at a variety of areas on the system that were affected by this malware.

The one question I have (and would have for anyone) is this statement that was made:

Further analysis shows that this appears to inject itself into running processes.

Given the rest of the writeup, there really isn't anything that specifically states how Brian determined this. I'm sure we can come up with a variety of assumptions as to how he did it, or how we would go about doing it, but I'd like to hear from the author. I'm going to submit that as a question to him, and I'll let you know what I find out.

How do you do that voodoo that you do?

After reading through the SecuriTeam documents, and then reading this SANS ISC post, I have to admit, incident response can be extremely complex. This is particularly true if the bad guys catch you with your pants down (figuratively, or hey, even literally). From the SecuriTeam write-ups, we get an insight into how systems are targetted...via Google searches (with books such as Google Hacking from Johnny Long, there's really no big mystery to this) and even freely available vulnerability scanning tools.

In the SecuriTeam documents, the decision to conduct a live response is documented, as a "full forensic analysis" would take too long...it was evidently determined that the attackers hadn't simply defaced a web page, but were actively on the system and involved in creating mayhem. This isn't unusual...many organizations decide that affected systems cannot be taken down. However, with the Team Evil incident, there didn't seem to be any volatile data collected or analyzed. It appears that because a web page was defaced and some directories created, that the investigation and the IR team's reactions focused solely on the web application(s).

One thing I took away from the second SecuriTeam document was that there were...what? Eight attacks?

The post from the Internet Storm Center doesn't seem to make things any easier, does it? After all, not only do multiple downloaders dump a "zoo of malware" (i.e., keylogger, BHOs, even disables the Security Center) on the system, but it also reports the infected system's location so it can be tracked via Google Maps. While this is an interesting new capability, the real issue IMHO is the stuff that's dumped on the system. How do you track it all? If you really don't know a great deal about your systems (hosts and networks) and the applications that you're running, and you haven't taken any real steps to protect those systems, I'd have to say that the ISC recommendation to reinstall is the only option.

If you really think about it, though, maybe this is the intention. If you've been looking at some of the various conference presentations over the past couple of years, there have been some anti-forensics and "how to use the analyst's training against them" presentations. One way to look at these attacks is that the attacker is just being greedy. Another is to think that the intention of dumping multiple programs (keyloggers, BHOs, etc.) on the system is that IF the sysadmin detects any one of them, they'll reinstall the system...and it's likely that the system can be easily reinfected.

So, on the face of things, we've got a denial of service attack...compromise and infect a critical-use system, and it's so important that the sysadmin takes it offline for a reinstall. This also lends itself to persistence...the reinstalled system may have the same or additional vulnerabilities, so the attacker can reinfect the system once it's back up.

Of course, I can't help but think that this could also be a distraction, a little bit of misdirection...get the IT staff looking one direction while the attacker is siphoning data off of another system.

So I guess I have to concede the point that reinstallation is the thing to do. If you (a) don't really know your infrastructure (hosts or network) that well, (b) have no idea where critical (processing or storing sensitive personal information) applications are, (c) haven't really taken any defense-in-depth measures, (d) have no clue what to do, and (e) don't have an IR plan that is supported and endorsed by senior management, I guess there really isn't any other option.

Thoughts?

Case Study from SecuriTeam

Everyone loves a case study! Don't we love to read when someone posts what they did when they responded to an incident? It's great, as it gives us a view into what others are doing. SecuriTeam has not one, but two such posts...well, one post that contains two case studies.

The first is a PDF of the incident write-up for a compromise that occurred in July 2006. The second is a follow-up, and both are very interesting.

I'm going to take a process-oriented view of things. Please don't ask me if someone who defaces web pages and knows some PHP code qualifies as a "cyber-terrorist". I don't want to get mixed up in semantics.

This whole thing seems to have started on or about 11 July 2006 with a web page defacement. Evidently, the bad guys gained access to a vulnerable system (found via Google) and installed a PHP 'shell'. Page 8 of the write-up specifies the need for a "real-time forensic analysis", due to the fact that not only did the good guys need to "stop the bleeding", but they had to counter the bad guys, who were not only deploying their own counter-measures, but attacking the good guys, as well. What's interesting about this is that on page 8, the authors mention having to battle active attacks from the bad guys, saying it was a "fight between the attackers...and the incident response personnel." Oddly, pages 9 - 11 included the 12 steps that the IR personnel went through, yet nothing was mentioned about having to battle an attack. The document continues into "Attack Methodology" and "Conclusions" with no mention of IR personnel being hammered by attacks from the bad guys.

Another interesting point is that the authors mention that the user-agent found in some web logs included the term "SIMBAR", and concluded (with no supporting info) that this meant that the attacker's system was infected with spyware. While I'm not discounting this, I do find it odd that no supporting information was provided. I did a search and found references to adware, but I also found a reference to the SIMS game, as well.

Continuing along into the follow-up report, "SIMBAR" is mentioned again, and this time the authors seem to believe that this user-agent indicates that the same computer was used in multiple attacks. IMHO, this is perhaps dubious at best, particularly if it is indicative of adware...adware can be fairly widespread. Also, beyond that, I'm not sure how significant this information really is to the overall incident.

Overall, both write-ups seem to indicate that the attackers used known exploits to gain access to systems, and used relatively known and easily available tools to gain their foothold. It also seems that the authors made several unsupported assumptions. At first the write-ups are interesting read, but when you really try to dig into them and get some meat, IMHO, it just isn't there.

But hey, who am I? What do you think?

Addendum 18 Nov: Besides the comments here, there's been corresponding posts over on TaoSecurity. I just want to say that I'm not trying to grill the authors of the documents, nor am I trying to point out every little detail that I think was mishandled...not at all. What I am saying is that I think the authors did a great job, but there are things that could have been handled a bit better. Richard Bejtlich mentions "focus and rigor" in one of his recent posts...just because something is done by volunteers, does that mean that quality should suffer?