In my last post, I mentioned that the FRU and FSP had been demos as part of the CERT VTE. Very cool. If you've read this blog for any period of time, you'll know that I've been interested in live response and forensic analysis of Windows systems for a while. One thing that the VTE demo showed me is that I really have to write up a user guide or manual for using the FSP tools, and then add a GUI to them.
That being said, I've been purusing the usual blogs for write ups regarding the recent BlackHat Federal conference. When you can't attend, reading other's impressions is the next best thing to being there. Kevin Mandia's presentation caught my eye, so I downloaded it and read through it. One of the things mentioned in the presentation is a "Live Response" tool that should be released by Kevin's company, Red Cliff Consulting, in January. After some discussion in the presentation on how incidents are detected, things that need to be collected are mentioned on slide 55 (there are 90 slides, folks, but the presentation is well worth the wait). The next slide contains a list of tools that can be run - while I agree with the tools for the most part, there are a couple that I'm not sure I'd run, but that's all covered in my book.
Slide 66 shows an image of the Live Response tool...it looks very interesting, and I really wish I'd been able to make it to the conference. I really like what I see in the presentation, overall...Kevin evidently went over several things (at least, in the slides) that I've been thinking about for some time now, such as the fact that live response is evolving due to the notification laws, with California's SB1386 being one of the first. In essence, companies need to know if client data has been compromised in anyway.
Thoughts? Where do we go from here? Is live response viable, particularly on Windows systems?
Sunday, January 29, 2006
Thursday, January 26, 2006
In search of...
No, this isn't a flashback to that old Leonard Nimoy show...it's about training. I got an email last night (don't have permission yet to say from whom) that pointed me to CERT's Virtual Training Environment. It's an online classroom, of sorts, where you can go, select a class, and watch it.
So I checked it out this morning. I went to the "Welcome to VTE" page, and clicked on "Launch VTE". Within seconds, I was looking at a list of topics. I saw "Forensics and Incident Response" and dove right in!
Once the choices of "classes" appeared, I saw that I could choose from documents, demos, and labs. What you get when you run one of the demos is basically a movie. Someone has a screen capture utility running while they narrate what they're doing, and they walk through things. The first one I looked at was "Analyzing Log Files with Notepad". It was pretty basic, but also pretty straightforward and really easy to follow.
There were a lot of other demos available, not all for Windows...there are some for Linux, as well. What I found most interesting, though, is that there is a "Configuration and Setup of the FCU" demo (it's my FRU, just misspelled), and a "Configuration and Setup of the FSP" module!
There's quite a bit of info at this site. The "Forensics" topic includes demos on EnCase, Autopsy, the use of dd, etc. It's very informative...take a look when you get a chance.
So I checked it out this morning. I went to the "Welcome to VTE" page, and clicked on "Launch VTE". Within seconds, I was looking at a list of topics. I saw "Forensics and Incident Response" and dove right in!
Once the choices of "classes" appeared, I saw that I could choose from documents, demos, and labs. What you get when you run one of the demos is basically a movie. Someone has a screen capture utility running while they narrate what they're doing, and they walk through things. The first one I looked at was "Analyzing Log Files with Notepad". It was pretty basic, but also pretty straightforward and really easy to follow.
There were a lot of other demos available, not all for Windows...there are some for Linux, as well. What I found most interesting, though, is that there is a "Configuration and Setup of the FCU" demo (it's my FRU, just misspelled), and a "Configuration and Setup of the FSP" module!
There's quite a bit of info at this site. The "Forensics" topic includes demos on EnCase, Autopsy, the use of dd, etc. It's very informative...take a look when you get a chance.
Wednesday, January 25, 2006
Cool Magazines
Recently, with the demise of Phrack, I've run across a couple of very interesting online magazines, or e-zines.
From Richard Bejtlich's TaoSecurity blog, the Uniformed, and the CodeBreaker's Journal. I haven't really taken the time to dig into either of these, but on the surface, they look like promising technical e-zines.
I ran across CheckMate today...pretty interesting first issue. This e-zine specifically targets computer forensics and incident response, and looks as if it may be a pretty good read. I went through one of the first articles on examining a user's browsing activities, and it provided pretty thorough coverage of the topic. One of the things I like most about the article is that it gave the reader information on how to interpret what they saw, rather than just pointing the reader to tools.
Know of any others?
From Richard Bejtlich's TaoSecurity blog, the Uniformed, and the CodeBreaker's Journal. I haven't really taken the time to dig into either of these, but on the surface, they look like promising technical e-zines.
I ran across CheckMate today...pretty interesting first issue. This e-zine specifically targets computer forensics and incident response, and looks as if it may be a pretty good read. I went through one of the first articles on examining a user's browsing activities, and it provided pretty thorough coverage of the topic. One of the things I like most about the article is that it gave the reader information on how to interpret what they saw, rather than just pointing the reader to tools.
Know of any others?
Tuesday, January 24, 2006
"Ooops, I did it again..."
No, this isn't a post about what would be on my iPod if I had one...it's even better.
Recently, the NSA posted a document entitled, "Redacting with Confidence: How to Safely Publish Sanitized Reports Converted From Word to PDF". I downloaded the document, because, well...I like metadata. I decided to see what metadata is in the PDF itself, and found this:
Title -> Redacting with Confidence: How to Safely Publish Sanitized Reports Converted from Word to PDF
Author -> SNAC
CreationDate -> D:20060110111526Z
ModDate -> D:20060120090543-05'00'
Creator -> activePDF DocConverter
Keywords -> word, pdf, redaction, metadata
Producer -> 5D PDFLib
Subject -> I333-015R-2005
Very nice. I pulled this out of the document using the pdfmeta.pl script listed on page 254 of my book.
Recently, the NSA posted a document entitled, "Redacting with Confidence: How to Safely Publish Sanitized Reports Converted From Word to PDF". I downloaded the document, because, well...I like metadata. I decided to see what metadata is in the PDF itself, and found this:
Title -> Redacting with Confidence: How to Safely Publish Sanitized Reports Converted from Word to PDF
Author -> SNAC
CreationDate -> D:20060110111526Z
ModDate -> D:20060120090543-05'00'
Creator -> activePDF DocConverter
Keywords -> word, pdf, redaction, metadata
Producer -> 5D PDFLib
Subject -> I333-015R-2005
Very nice. I pulled this out of the document using the pdfmeta.pl script listed on page 254 of my book.
Thursday, January 12, 2006
The need for IR training
This ComputerWorld article caught my eye this morning...I've done vulnerability assessments before, and I fully agree with all of these mistakes. They do, in fact, occur.
Each of the mistakes has earned it's rightful place in precedence. I started doing vulnerability scanning, commercially, in 1997. This has always included much more than simply running a scanning tool, but what occurred then continues today...we'd deliver our report, and most customers would thank us...and that was it. In some very few cases, some of the issues would be fixed, but mostly due to infrastructure changes, upgrades, etc.
The big one that jumps out at me know, though is number 5 - "Being unprepared for the unknown". To me, this is an issue of being prepared for incidents. The real world has all sorts of incident response capability. I've been on plains with rescue dogs that go to Washington, DC, once a year for testing...they'd been involved in the 9/11 search and rescue, and their condition is being tracked for any signs of health issues. We see cops and firefighters on the news. Ever hear of "smoke jumpers"? Heck, even the military is an "incident response capability" in and of itself.
So look around your IT shop right now. What's your incident response capability? If you're reading this, it's probably you. Are you prepared? How do you recognize or receive notification that an incident has occurred? Is it based on known signatures?
Are you prepared for zero-day exploits?
And don't think for an instant that you can't be prepared for these. I know what some of you are saying, that by definition, one can't be prepared for a "zero-day", because it isn't known. Well, I'm hear to tell you...you're wrong. You're prepared if you know that not all malware processes appear in the Task Manager as "danger.exe" or "malware.exe". Do you know how to get more information about processes, about what's running on a system? Can you triage a system? Can you gather specific information from a system, so that you (or someone else) has a fairly complete snapshot of what's going on and can at least begin to figure out what's going on?
Here's another consideration...what do you watch at night? Are you a CSI fan? How about House? Watch a couple episodes of House and start thinking about how you'd perform a "differential diagnosis" of a system.
Looking at the ComputerWorld article one last time, I guess, in a way, my mind ties all of the mistakes back to training issues and misconceptions...chicken. Egg.
Each of the mistakes has earned it's rightful place in precedence. I started doing vulnerability scanning, commercially, in 1997. This has always included much more than simply running a scanning tool, but what occurred then continues today...we'd deliver our report, and most customers would thank us...and that was it. In some very few cases, some of the issues would be fixed, but mostly due to infrastructure changes, upgrades, etc.
The big one that jumps out at me know, though is number 5 - "Being unprepared for the unknown". To me, this is an issue of being prepared for incidents. The real world has all sorts of incident response capability. I've been on plains with rescue dogs that go to Washington, DC, once a year for testing...they'd been involved in the 9/11 search and rescue, and their condition is being tracked for any signs of health issues. We see cops and firefighters on the news. Ever hear of "smoke jumpers"? Heck, even the military is an "incident response capability" in and of itself.
So look around your IT shop right now. What's your incident response capability? If you're reading this, it's probably you. Are you prepared? How do you recognize or receive notification that an incident has occurred? Is it based on known signatures?
Are you prepared for zero-day exploits?
And don't think for an instant that you can't be prepared for these. I know what some of you are saying, that by definition, one can't be prepared for a "zero-day", because it isn't known. Well, I'm hear to tell you...you're wrong. You're prepared if you know that not all malware processes appear in the Task Manager as "danger.exe" or "malware.exe". Do you know how to get more information about processes, about what's running on a system? Can you triage a system? Can you gather specific information from a system, so that you (or someone else) has a fairly complete snapshot of what's going on and can at least begin to figure out what's going on?
Here's another consideration...what do you watch at night? Are you a CSI fan? How about House? Watch a couple episodes of House and start thinking about how you'd perform a "differential diagnosis" of a system.
Looking at the ComputerWorld article one last time, I guess, in a way, my mind ties all of the mistakes back to training issues and misconceptions...chicken. Egg.
Wednesday, January 11, 2006
What is "security"??
Good question. We each approach topics like this differently, based on our background, experiences, etc. This thread on Slashdot caught my eye this morning, as did Brian Kreb's latest blog entry on SecurityFix (careful folks, it's a long blog entry, but an excellent read nonetheless).
My background in security started with pen-tests, war-dialing, and vulnerability assessments. I've also done policy development, etc. I've had a hand in incident response and forensics, as well. This is very different from Bill Gate's background...so we view security differently. The Microsoft stance has been to support better security practices and there have been intiatives with regards to security...so in light of things like SoBig, CodeRed, Nimda, and the more recent WMF issues, can we say that Micrsofot has failed?
Before giving you my thoughts, let me tell you about something that happened to me back on '00. I was working at a now-defunct telecomm company, as part of the corporate security staff. There was a rogue group of guys who claimed that they had security responsibilities, but you could never really tie them down...they were like kids who were told to not to do something, but they did it anyway. So, at one point, one of the guys from the team comes over and tells me how his group had identified an issue and confiscated a system. When they confronted the employee (without the presence of or even notifying HR, BTW...), the employee denied any knowledge of the issue. So these guys hired an outside consulting firm to come in and do forensic analysis of the hard drive...and the tasking they gave was to locate any files specific to the SubSeven Trojan/backdoor. That's it.
So this guy tells me that he looked at the hard drive and found a hidden DOS partition. He told me that we shouldn't deal with this company b/c in his mind, they didn't know what they were doing.
We (my boss and I) sat down and talked to the forensic analyst from the company. He showed us the tasking, and their final report. The documents clearly stated that the sole tasking was to locate files associated with SubSeven, which the company did (and to be honest, pretty much anyone could have done at the time).
So the question is, did the company "fail" or perform poorly? The analyst said that he'd identified the hidden DOS partition, but that partition did not contain the files in question. Since it wasn't part of the tasking, and the company was never given any information regarding the overall case or issue, they provided what they were asked for.
Now, back to the issue with Microsoft. I think what this all boils down to is a matter of expectations. When someone high up the food chain within Microsoft gets up on stage, most of the security guys in the audience hear "blahblahblahsecurityblahblah". They then fill in the gaps surrounding "security" with their own expectations, and feel justified pointing out failures. But wait a second...had they listened to the speaker, they might have heard him (or her) set those expectations and define "success" in their own context.
So, on the one hand, you can look at what Microsoft has done to improve security with things like a firewall for XP, and IIS 6.x functionality that's "off" by default as successful steps toward better "security". But does the recent WMF exploit issue really show that Microsoft has failed overall? Perhaps not. Microsoft's stance seems to be, "yeah, we know that this issue has been around since Windows 3.0, but there haven't been any publicly available exploits until now, and we had higher priority things to work on." Can you get mad at them for that? Really? I mean, don't we do the exact some thing everyday? Don't we have limited resources (time, money, etc.) and make decisions about what's important to us? How do we then feel when someone comes back to us and says that we "failed", but their determination of success is different from our own?
Maybe the approach that needs to be taken is different. Maybe what needs to happen is that more of Microsoft's customers need to get together and say, "hey, this stuff you've done is all well and good, but you know, malware, worms and rootkits are really kicking our butts...can you help us out?" Maybe if enough customers said this, Horton would hear the Who (NOT Roger Daltry). After all, haven't customers gotten Microsoft to redefine "success" before? Didn't someone from Microsoft say back in the early '90s that the Internet would never become what it has, in fact, become today?
My background in security started with pen-tests, war-dialing, and vulnerability assessments. I've also done policy development, etc. I've had a hand in incident response and forensics, as well. This is very different from Bill Gate's background...so we view security differently. The Microsoft stance has been to support better security practices and there have been intiatives with regards to security...so in light of things like SoBig, CodeRed, Nimda, and the more recent WMF issues, can we say that Micrsofot has failed?
Before giving you my thoughts, let me tell you about something that happened to me back on '00. I was working at a now-defunct telecomm company, as part of the corporate security staff. There was a rogue group of guys who claimed that they had security responsibilities, but you could never really tie them down...they were like kids who were told to not to do something, but they did it anyway. So, at one point, one of the guys from the team comes over and tells me how his group had identified an issue and confiscated a system. When they confronted the employee (without the presence of or even notifying HR, BTW...), the employee denied any knowledge of the issue. So these guys hired an outside consulting firm to come in and do forensic analysis of the hard drive...and the tasking they gave was to locate any files specific to the SubSeven Trojan/backdoor. That's it.
So this guy tells me that he looked at the hard drive and found a hidden DOS partition. He told me that we shouldn't deal with this company b/c in his mind, they didn't know what they were doing.
We (my boss and I) sat down and talked to the forensic analyst from the company. He showed us the tasking, and their final report. The documents clearly stated that the sole tasking was to locate files associated with SubSeven, which the company did (and to be honest, pretty much anyone could have done at the time).
So the question is, did the company "fail" or perform poorly? The analyst said that he'd identified the hidden DOS partition, but that partition did not contain the files in question. Since it wasn't part of the tasking, and the company was never given any information regarding the overall case or issue, they provided what they were asked for.
Now, back to the issue with Microsoft. I think what this all boils down to is a matter of expectations. When someone high up the food chain within Microsoft gets up on stage, most of the security guys in the audience hear "blahblahblahsecurityblahblah". They then fill in the gaps surrounding "security" with their own expectations, and feel justified pointing out failures. But wait a second...had they listened to the speaker, they might have heard him (or her) set those expectations and define "success" in their own context.
So, on the one hand, you can look at what Microsoft has done to improve security with things like a firewall for XP, and IIS 6.x functionality that's "off" by default as successful steps toward better "security". But does the recent WMF exploit issue really show that Microsoft has failed overall? Perhaps not. Microsoft's stance seems to be, "yeah, we know that this issue has been around since Windows 3.0, but there haven't been any publicly available exploits until now, and we had higher priority things to work on." Can you get mad at them for that? Really? I mean, don't we do the exact some thing everyday? Don't we have limited resources (time, money, etc.) and make decisions about what's important to us? How do we then feel when someone comes back to us and says that we "failed", but their determination of success is different from our own?
Maybe the approach that needs to be taken is different. Maybe what needs to happen is that more of Microsoft's customers need to get together and say, "hey, this stuff you've done is all well and good, but you know, malware, worms and rootkits are really kicking our butts...can you help us out?" Maybe if enough customers said this, Horton would hear the Who (NOT Roger Daltry). After all, haven't customers gotten Microsoft to redefine "success" before? Didn't someone from Microsoft say back in the early '90s that the Internet would never become what it has, in fact, become today?
Thursday, January 05, 2006
How are you spending your security dollars?
I was reading some comments on another blog today, and one comment in particular caught my eye. A retired CIO lamented the fact that "millions of dollars" were spent providing security to Windows systems...but he put a Mac on the network and never had a problem. Yeah, you read it right..."millions", with an M.
Ugh. My dooty detector goes off, screaming like a banshee, whenever a C-level executive makes comments like that. No, I'm not going to break things down to a para-religious argument over who's OS is better. That's not where I'm going with this one. What I am leading to here is, this sounds like a training issue to me. It sounds like the knowledge level of the IT staff has...shall we say...room for improvement.
Now, I have no doubt that there are some really bright, very knowledgeable IT guys and gals out there, so if this doesn't apply to you, feel free to leave the room.
I was a security weenie at a company once, and the senior admin guy had a bunch of guys working for him. The senior admin guy went to his desktop support guy, a legitimate Dude Among Dudes, and told him, "we can't promote you to an administrator, like I promised, until you get your MCSE." I heard that and thought it was funny...not laughing funny, but "here, try this, it tastes like crap" funny...because none of the current IT administrator staff had an MCSE. Yep, you read that right..."none", with an N.
My point of all this is that this Dude, who'd helped me with virus eradication, was knowledgeable and had a good head on his shoulders (and still does). The admins who wouldn't let him play in their reindeer games, botched pretty much every incident they responded to, had no documentation and had no network diagram. They didn't even know where the egress points were...the ones that bypassed the firewall...even though they'd set them up.
Okay, getting back on track here...where was I? Oh, yeah...training. My thought is this...when it comes to securing any network, regardless of operating systems and applications, you need to start with documentation. If you don't have it, then getting it is going to be a very necessary exercise. This is a good place to start when identifying your risks. Why? Because you have to know what your risks are so that you can start mitigating them...right?
What I'm getting at here is that spending "millions of dollars" to secure Windows systems probably wasn't necessary. If you don't know what you're doing, then of course trying to secure a network is going to be expensive. I simply think that that kind of money would be better spent on things like hiring better qualified personnel, and training the ones you have.
Oh, one other thing...if you're reading this blog entry, then let me throw this out. There are training opportunities available from a variety of sources, at a variety of price points. But what would you say if you could get your entire staff (like, 12 - 20 people) training, with that training targetted to your needs (for your environment), for less than it takes to send 2 or 3 people away to some of the bigger training events? How about if that training led to follow-on training and services that continued to apply specifically to your needs? Would you be interested in something like this?
Ugh. My dooty detector goes off, screaming like a banshee, whenever a C-level executive makes comments like that. No, I'm not going to break things down to a para-religious argument over who's OS is better. That's not where I'm going with this one. What I am leading to here is, this sounds like a training issue to me. It sounds like the knowledge level of the IT staff has...shall we say...room for improvement.
Now, I have no doubt that there are some really bright, very knowledgeable IT guys and gals out there, so if this doesn't apply to you, feel free to leave the room.
I was a security weenie at a company once, and the senior admin guy had a bunch of guys working for him. The senior admin guy went to his desktop support guy, a legitimate Dude Among Dudes, and told him, "we can't promote you to an administrator, like I promised, until you get your MCSE." I heard that and thought it was funny...not laughing funny, but "here, try this, it tastes like crap" funny...because none of the current IT administrator staff had an MCSE. Yep, you read that right..."none", with an N.
My point of all this is that this Dude, who'd helped me with virus eradication, was knowledgeable and had a good head on his shoulders (and still does). The admins who wouldn't let him play in their reindeer games, botched pretty much every incident they responded to, had no documentation and had no network diagram. They didn't even know where the egress points were...the ones that bypassed the firewall...even though they'd set them up.
Okay, getting back on track here...where was I? Oh, yeah...training. My thought is this...when it comes to securing any network, regardless of operating systems and applications, you need to start with documentation. If you don't have it, then getting it is going to be a very necessary exercise. This is a good place to start when identifying your risks. Why? Because you have to know what your risks are so that you can start mitigating them...right?
What I'm getting at here is that spending "millions of dollars" to secure Windows systems probably wasn't necessary. If you don't know what you're doing, then of course trying to secure a network is going to be expensive. I simply think that that kind of money would be better spent on things like hiring better qualified personnel, and training the ones you have.
Oh, one other thing...if you're reading this blog entry, then let me throw this out. There are training opportunities available from a variety of sources, at a variety of price points. But what would you say if you could get your entire staff (like, 12 - 20 people) training, with that training targetted to your needs (for your environment), for less than it takes to send 2 or 3 people away to some of the bigger training events? How about if that training led to follow-on training and services that continued to apply specifically to your needs? Would you be interested in something like this?
New NIST document (draft)
I was reviewing the updated E-evidence.info site this morning, and one of the interesting things I came across was the draft NIST SP800-86, Guide to Computer and Network Data Analysis: Applying Forensic Techniques to Incident Response.
As I read through the document for the first time, it's clear that this is a great place to start. From my perspective, I'm glad to see a short, 2 paragraph discussion of NTFS alternate data streams on page 4-5 of the document. The author's did provide footnotes with links to URLs for more information. There's also a section on collecting volatile data from systems.
It's a good resource, that's for sure. Take a look when you get a chance.
As I read through the document for the first time, it's clear that this is a great place to start. From my perspective, I'm glad to see a short, 2 paragraph discussion of NTFS alternate data streams on page 4-5 of the document. The author's did provide footnotes with links to URLs for more information. There's also a section on collecting volatile data from systems.
It's a good resource, that's for sure. Take a look when you get a chance.
Tuesday, December 27, 2005
The Mystery of MUICache...solved??
Holy Registry keys, Batman!
Okay, I've been tossing this around for a while, and even put it on the back burner, but never completely forgot about it. The issue is this MUICache Registry key, or more specifically:
HKEY_CURRENT_USER\Software\Microsoft\Windows\ShellNoRoam\MUICache
This is an issue, as a while back, I started noticing references to malware creating values beneath this key...specifically, Trojan-Alexmo and Adware-BlowSearch. The technical write ups simply stated that the keys were created, but gave no indication as to their use. Was this a new startup location that malware authors had discovered? What is the key used for? I did some searches, but found way too much information to wade through and digest. I posted questions, but didn't get responses.
So, I'm over on ForensicFocus today, and "Lance" (I'm assuming this is the Guidance Lance) says something about the MUICache key values that point executables having window names as their values. You know, when you open up the command prompt on XP, for example, it says "Command Prompt" as the title (Trivia Question: Does anyone remember how to change that title in a DOS batch file, so something other than "Command Prompt" appears??) of the window. Well, I opened up my RegEdit and took a look at the entries under the key. I took a close look at some of the values that pointed to executables, and tried opening some. I began to see that the information in the Registry wasn't what I was seeing as the window titles.
So then I fired up Perl, and ran a script that I use that retrieves file version information from executables (ie, EXE, DLL, etc.). Lo and behold, but there under the FileDescription value, was the string that I was looking at in the Registry!
So, what does this mean? Well, I started doing searches for "Muicache + filedescription" and I found this archived entry from the OldNewThing blog. From there, I found others...in particular, this one from the Sun Java forum.
From reading through these entries, my understanding of this issue is that the values that you see under the MUICache key are not placed there by the executable, but by the shell (ie, Explorer.exe). Therefore, when a technical description of malware states that the executable "creates an entry under the MUICache key", this isn't technically correct. In fact, what's happening is that the shell is creating the entry when the malware is run.
From the forensic analysis aspect of things, how does this help us? Well, it shows that an application was run on an XP (I don't have a Win2k system to test right now) system at some point, whether the executable is there or not. However, we don't know when the application was run, as there is no MRUList associated with the entries. One indicator may be a corresponding entry for the executable in the PreFetch directory.
Well, it would seem that the veil of secrecy on that particular issue has been pierced...at least, to a degree. There are still questions, such as, is there a limit on the number of entries in this key?
Also, there needs to be some testing done. For example, if someone gets a Trojan on a system, and gets the user to launch it somehow, one would think that an entry would appear beneath the key. However, if the attacker were able to get another executable on the system, and launch it via the Trojan (something as simple as a netcat listener would suffice for testing), would an entry be made for that second executable? It would stand to reason that malware that runs as a service wouldn't appear in this entry, because such applications are not tied usually tied to an interactive user's account.
Thoughts?
Addendum 30 Dec: In case it wasn't clear, one of the points to my entry is that at least on A/V vendor had done "analysis" of some of the new malware (linked) and found that one of the changes that occurred on the system was that values were added to the MUICache key. Googling for this kind of thing reveals "analyses" at other A/V sites that include equally vague information. However, it seems that this key is NOT, in fact, set by the malware in question but instead by the shell.
So, as an aside, whom do you trust when it comes to this kind of analysis?
Okay, I've been tossing this around for a while, and even put it on the back burner, but never completely forgot about it. The issue is this MUICache Registry key, or more specifically:
HKEY_CURRENT_USER\Software\Microsoft\Windows\ShellNoRoam\MUICache
This is an issue, as a while back, I started noticing references to malware creating values beneath this key...specifically, Trojan-Alexmo and Adware-BlowSearch. The technical write ups simply stated that the keys were created, but gave no indication as to their use. Was this a new startup location that malware authors had discovered? What is the key used for? I did some searches, but found way too much information to wade through and digest. I posted questions, but didn't get responses.
So, I'm over on ForensicFocus today, and "Lance" (I'm assuming this is the Guidance Lance) says something about the MUICache key values that point executables having window names as their values. You know, when you open up the command prompt on XP, for example, it says "Command Prompt" as the title (Trivia Question: Does anyone remember how to change that title in a DOS batch file, so something other than "Command Prompt" appears??) of the window. Well, I opened up my RegEdit and took a look at the entries under the key. I took a close look at some of the values that pointed to executables, and tried opening some. I began to see that the information in the Registry wasn't what I was seeing as the window titles.
So then I fired up Perl, and ran a script that I use that retrieves file version information from executables (ie, EXE, DLL, etc.). Lo and behold, but there under the FileDescription value, was the string that I was looking at in the Registry!
So, what does this mean? Well, I started doing searches for "Muicache + filedescription" and I found this archived entry from the OldNewThing blog. From there, I found others...in particular, this one from the Sun Java forum.
From reading through these entries, my understanding of this issue is that the values that you see under the MUICache key are not placed there by the executable, but by the shell (ie, Explorer.exe). Therefore, when a technical description of malware states that the executable "creates an entry under the MUICache key", this isn't technically correct. In fact, what's happening is that the shell is creating the entry when the malware is run.
From the forensic analysis aspect of things, how does this help us? Well, it shows that an application was run on an XP (I don't have a Win2k system to test right now) system at some point, whether the executable is there or not. However, we don't know when the application was run, as there is no MRUList associated with the entries. One indicator may be a corresponding entry for the executable in the PreFetch directory.
Well, it would seem that the veil of secrecy on that particular issue has been pierced...at least, to a degree. There are still questions, such as, is there a limit on the number of entries in this key?
Also, there needs to be some testing done. For example, if someone gets a Trojan on a system, and gets the user to launch it somehow, one would think that an entry would appear beneath the key. However, if the attacker were able to get another executable on the system, and launch it via the Trojan (something as simple as a netcat listener would suffice for testing), would an entry be made for that second executable? It would stand to reason that malware that runs as a service wouldn't appear in this entry, because such applications are not tied usually tied to an interactive user's account.
Thoughts?
Addendum 30 Dec: In case it wasn't clear, one of the points to my entry is that at least on A/V vendor had done "analysis" of some of the new malware (linked) and found that one of the changes that occurred on the system was that values were added to the MUICache key. Googling for this kind of thing reveals "analyses" at other A/V sites that include equally vague information. However, it seems that this key is NOT, in fact, set by the malware in question but instead by the shell.
So, as an aside, whom do you trust when it comes to this kind of analysis?
Friday, December 23, 2005
Registry Reference
I've been working away on a Registry reference, basically, an Excel spreadsheet of Registry keys. The idea is to list them with some sort of categorization, listing each by key name/path, value (if applicable), a brief description, and then any references that may apply.
In the case of what I'm working on, most of the references so far are MS KB articles that describe the keys and/or values.
The descriptions are meant to provide information regarding how these keys/values are useful during forensic investigations. Many of them can also be useful during live response investigations, as well.
Work is coming along smoothly...oddly enough there isn't a great deal of this sort of information out there. I've been pointed to several resources, and in most cases they lead back to either my original spreadsheet, or stuff from AccessData.
In the case of what I'm working on, most of the references so far are MS KB articles that describe the keys and/or values.
The descriptions are meant to provide information regarding how these keys/values are useful during forensic investigations. Many of them can also be useful during live response investigations, as well.
Work is coming along smoothly...oddly enough there isn't a great deal of this sort of information out there. I've been pointed to several resources, and in most cases they lead back to either my original spreadsheet, or stuff from AccessData.
Thursday, December 22, 2005
The age of "Nintendo forensics"...
...is coming to a close. Or, rather, it needs to. Looking around, seeing what's going on in the community, and in particular, in the news, I have to think that the days of blindly imaging a system and then running searches for keywords or images are going to be a thing of the past soon.
Windows systems in particular hold a wealth of information. There are areas of systems that are largely unexplored by many forensic analysts, particularly on the law enforcement side of the house. Now, I know that this is in large part due to case loads, staffing, training, and simply time. However, more knowledgeable law enforcement officers (at all levels...local, state, and even federal) as well as more knowledgeable system administrators (and even CIOs) will serve to level the playing field between the good guys and the bad guys.
What am I talking about? I'm talking about the fact that Windows XP and 2003 are becoming more prevalent by the day, and soon Vista will be in production and on the streets. We (the forensic community) can no longer operate from an MS-DOS standpoint.
Don't get me wrong...data reduction through the use of searches, file hashes, etc., is still extremely useful. However, a search for an ASCII string may turn up very little when searching the Windows Registry. One needs to understand the format of the Registry (even on the binary level) and how the Registry is structured. The same holds true with other file formats...OLE/compound documents (MS Word being the most prevalent example), PE files, Event Log files, INFO2 files, and even shortcuts. Yes, there are tools that can be run to pull information from the files but does the person running the tool understand what's happening "under the hood"?
Now, some of you are going to say, "Hey, I don't need to know how to locate and program the computer systems in my car in order to drive a car.", and I'd say, "You're right." However, what I'm talking about is pulling more comprehensive information from an image of a Windows system, and building a better case. In the face of more sophisticated malware, the expanding use of rootkits, and the increase of publicized anti-forensic techniques, I'm beginning to see how a greater level of knowledge is necessary.
Windows systems in particular hold a wealth of information. There are areas of systems that are largely unexplored by many forensic analysts, particularly on the law enforcement side of the house. Now, I know that this is in large part due to case loads, staffing, training, and simply time. However, more knowledgeable law enforcement officers (at all levels...local, state, and even federal) as well as more knowledgeable system administrators (and even CIOs) will serve to level the playing field between the good guys and the bad guys.
What am I talking about? I'm talking about the fact that Windows XP and 2003 are becoming more prevalent by the day, and soon Vista will be in production and on the streets. We (the forensic community) can no longer operate from an MS-DOS standpoint.
Don't get me wrong...data reduction through the use of searches, file hashes, etc., is still extremely useful. However, a search for an ASCII string may turn up very little when searching the Windows Registry. One needs to understand the format of the Registry (even on the binary level) and how the Registry is structured. The same holds true with other file formats...OLE/compound documents (MS Word being the most prevalent example), PE files, Event Log files, INFO2 files, and even shortcuts. Yes, there are tools that can be run to pull information from the files but does the person running the tool understand what's happening "under the hood"?
Now, some of you are going to say, "Hey, I don't need to know how to locate and program the computer systems in my car in order to drive a car.", and I'd say, "You're right." However, what I'm talking about is pulling more comprehensive information from an image of a Windows system, and building a better case. In the face of more sophisticated malware, the expanding use of rootkits, and the increase of publicized anti-forensic techniques, I'm beginning to see how a greater level of knowledge is necessary.
Visibility?
Posts have been sporadic, and not nearly as frequent as before...I know. That'll change.
For now, though, I've got a question for the readers...one that you can really help me with. Just about every month, I run across someone (usually online) who says, "I wish I knew more about this...". In the past, it was things like NTFS alternate data streams. More recently, it's been USB device artifacts in the Registry. The thing is, regardless of the topic, I will do a simple Google search and turn up some pretty good resources (if it's stuff I've done, I cheat a little and just send them the link).
So, my question is this...how do you make things more visible? Take information as an example. You write an article about something that may be very useful to a group of people. You get the article published in a magazine or journal that caters to that group of people. However, not everyone in that group gets the journal.
Things I've tried include presenting at conferences (and in the case of my book, giving away free copies after the presentation), writing articles, posting to online forums, talking to people, etc. Now, I'm not saying that that's all that can be done, or that I've done any of those things enough. What I am asking is, what are some things that I can do to market stuff I've done...not just books, but code and any other information that I develop/produce.
Thanks...thoughts and especially solutions are appreciated.
For now, though, I've got a question for the readers...one that you can really help me with. Just about every month, I run across someone (usually online) who says, "I wish I knew more about this...". In the past, it was things like NTFS alternate data streams. More recently, it's been USB device artifacts in the Registry. The thing is, regardless of the topic, I will do a simple Google search and turn up some pretty good resources (if it's stuff I've done, I cheat a little and just send them the link).
So, my question is this...how do you make things more visible? Take information as an example. You write an article about something that may be very useful to a group of people. You get the article published in a magazine or journal that caters to that group of people. However, not everyone in that group gets the journal.
Things I've tried include presenting at conferences (and in the case of my book, giving away free copies after the presentation), writing articles, posting to online forums, talking to people, etc. Now, I'm not saying that that's all that can be done, or that I've done any of those things enough. What I am asking is, what are some things that I can do to market stuff I've done...not just books, but code and any other information that I develop/produce.
Thanks...thoughts and especially solutions are appreciated.
Thursday, December 01, 2005
Registry Reference
One thing I've really noticed over the years is that while some information is available out there on some Registry keys and values, there really isn't much that is useful/credible and geared toward forensic analysis. So I've been considering starting up a reference resource...well, I brought the subject up on a couple of lists, mostly looking for input, and the overwhelming response was, "Great! Let me know what I can do to help."
I haven't really settled on a format, per se, outside of basic elements, such as key/value path, data type of the value(s), a description or explanation of the key/value and what conditions lead to the creation/modification of the key/value, credible references, and the name of the submitter. One thought I had was to list everything in HTML, making it easily portable. Another thought was to use a database of some sort, because in doing so, scripts can be written to search the database, or extract information into text, HTML, XML, etc....whatever format suits the user.
Again, the goal is to provide credible, referenced information about Registry keys, as Registry analysis is something that simply hasn't been explored up to this point...at least, not in any great depth.
If you've got any thoughts on this, let me know. And yes, I am aware of the paper AccessData put out...thanks.
I haven't really settled on a format, per se, outside of basic elements, such as key/value path, data type of the value(s), a description or explanation of the key/value and what conditions lead to the creation/modification of the key/value, credible references, and the name of the submitter. One thought I had was to list everything in HTML, making it easily portable. Another thought was to use a database of some sort, because in doing so, scripts can be written to search the database, or extract information into text, HTML, XML, etc....whatever format suits the user.
Again, the goal is to provide credible, referenced information about Registry keys, as Registry analysis is something that simply hasn't been explored up to this point...at least, not in any great depth.
If you've got any thoughts on this, let me know. And yes, I am aware of the paper AccessData put out...thanks.
Tuesday, November 01, 2005
Finding a rootkit
Mark Russinovich over on SysInternals.com posted a blog entry yesterday about how he located a rootkit that was installed after he purchased a CD.
One has to raise the "HUH??!?!" flag (those are the three letters I chose, but I'm sure that there are other blog posts out there on this subject that will be brought to you by the letters "W", "T", and "F"...) on this one.
The SANS Internet Storm Center picked it up, as well. So did F-Secure, and they have their own technical description here.
So...imagine if you will...not only are you looking over your shoulder with regards to the bad guys and malcode, but now you have to be careful of the legitimate guys, as well. Sony is legitimate, right? What happens if a worm comes out that doesn't have its own rootkit payload (there was a worm for AIM recently that did), but instead looks for the presence of a commercial DRM rootkit, and hides itself that way? What will that worm be called? "W32.SonyPiggyback"?
Face it folks...do a search on SARC for "rootkit" and see how many entries you find over last year. Ouch!
Addendum 3 Nov: I generally try to stay on-track in this space, my blog...keeping on topic with regards to forensic analysis of Windows systems. However, I have to say that Wired really has it wrong. Specifically, "But in our view, the hacker and virus threat is something of a red herring...". Red herring? How so? The article goes on to say, "Sony may even have committed a crime under the U.S. Computer Fraud and Abuse Act...".
Wow. The EULA doesn't specifically state that its installing a rootkit, but given the knee-jerk reactions of most folks, is anyone really surprised? After all, it was just last February that Microsoft hit the stage of the RSA Conference, full of sound and fury over rootkits, but signifying nothing. So they bring something that's been around for a while to the forefront of attention...and because Microsoft said it, the media jumps all over it. And guess what? There are even courses you can take in writing rootkits. So...someone in Sony is trying to figure out how to protect their "property", and look what they stumble across.
Should Sony be faulted for what they did...perhaps. Should they be faulted more so than other companies (a company is a business, remember...a real-world construct designed to make money) who've taken "extreme" measures that end up making self-righteous folks indignant?
I'm not making a call on that. What I am concerned about is the number of folks out there who've installed this stuff, and suddenly there are a whole bunch of other files on the system with the same prefix (in this case, "$sys$"). I'm concerned about the first worm that does a check for the Sony stuff...why download your own stealth technology when there's already a perfectly good one on the system.
Okay, enough of that. Brian Krebs picked up on this and blogged...if you have a few minutes, scroll through some of the responses. Maybe you'll feel moved to leave a comment...
One has to raise the "HUH??!?!" flag (those are the three letters I chose, but I'm sure that there are other blog posts out there on this subject that will be brought to you by the letters "W", "T", and "F"...) on this one.
The SANS Internet Storm Center picked it up, as well. So did F-Secure, and they have their own technical description here.
So...imagine if you will...not only are you looking over your shoulder with regards to the bad guys and malcode, but now you have to be careful of the legitimate guys, as well. Sony is legitimate, right? What happens if a worm comes out that doesn't have its own rootkit payload (there was a worm for AIM recently that did), but instead looks for the presence of a commercial DRM rootkit, and hides itself that way? What will that worm be called? "W32.SonyPiggyback"?
Face it folks...do a search on SARC for "rootkit" and see how many entries you find over last year. Ouch!
Addendum 3 Nov: I generally try to stay on-track in this space, my blog...keeping on topic with regards to forensic analysis of Windows systems. However, I have to say that Wired really has it wrong. Specifically, "But in our view, the hacker and virus threat is something of a red herring...". Red herring? How so? The article goes on to say, "Sony may even have committed a crime under the U.S. Computer Fraud and Abuse Act...".
Wow. The EULA doesn't specifically state that its installing a rootkit, but given the knee-jerk reactions of most folks, is anyone really surprised? After all, it was just last February that Microsoft hit the stage of the RSA Conference, full of sound and fury over rootkits, but signifying nothing. So they bring something that's been around for a while to the forefront of attention...and because Microsoft said it, the media jumps all over it. And guess what? There are even courses you can take in writing rootkits. So...someone in Sony is trying to figure out how to protect their "property", and look what they stumble across.
Should Sony be faulted for what they did...perhaps. Should they be faulted more so than other companies (a company is a business, remember...a real-world construct designed to make money) who've taken "extreme" measures that end up making self-righteous folks indignant?
I'm not making a call on that. What I am concerned about is the number of folks out there who've installed this stuff, and suddenly there are a whole bunch of other files on the system with the same prefix (in this case, "$sys$"). I'm concerned about the first worm that does a check for the Sony stuff...why download your own stealth technology when there's already a perfectly good one on the system.
Okay, enough of that. Brian Krebs picked up on this and blogged...if you have a few minutes, scroll through some of the responses. Maybe you'll feel moved to leave a comment...
Wednesday, October 26, 2005
Peeking inside Word documents
I was chatting with someone yesterday who asked me where I found the files I used to test the Word Metadata Dumper, and I simply said, "Google."
Yep, that's right...I just Googled for Word documents from the .mil domain, as well as the .gov domain. Wanna know how to search Google for all sorts of other goodies? Check out Johnny Long's web site, or grab a copy of his book on "Google hacking".
Want to get a little up-close-and-personal with someone else, maybe even someone else you don't know? Remember the "Extreme File Sharing" post from Security Fix? I'd tried it and found some of the very same things...files left behind by malware with keylogger capability, etc.
Yep, that's right...I just Googled for Word documents from the .mil domain, as well as the .gov domain. Wanna know how to search Google for all sorts of other goodies? Check out Johnny Long's web site, or grab a copy of his book on "Google hacking".
Want to get a little up-close-and-personal with someone else, maybe even someone else you don't know? Remember the "Extreme File Sharing" post from Security Fix? I'd tried it and found some of the very same things...files left behind by malware with keylogger capability, etc.
Tuesday, October 25, 2005
Sleuthkit on Windows
Hey, guess what I did last night!! I installed Sleuthkit and Autopsy on Windows XP!
For you Linux and *BSD gurus who felt a nauseating disturbance in the Force...it wasn't that burrito you had...it was me!
Okay, okay...it wasn't just me...I had help.
When I'm working with things on my home systems and looking at forensic analysis, I like to use ProDiscover to grab a dd image of a VMWare session, my thumb drive, etc. As it turns out, I had a 5GB image of an XP Pro system, so I copied that over to the evidence locker and fired up Autopsy. I didn't run completely through many of the things that I could have done, because it would take some time to do so...but as far as the things I did try, they worked great.
Don't have an image of your own to play with? Well, the instructions for installing Sleuthkit and Autopsy on Windows also has instructions for how to image a floppy drive...so, you can entertain and amaze your friends by recovering deleted files! Or, you can go to the Digitial Forensics Tool Testing site and grab an image or two to work with.
My hat's off to Brian Carrier, for having created these tools.
For you Linux and *BSD gurus who felt a nauseating disturbance in the Force...it wasn't that burrito you had...it was me!
Okay, okay...it wasn't just me...I had help.
When I'm working with things on my home systems and looking at forensic analysis, I like to use ProDiscover to grab a dd image of a VMWare session, my thumb drive, etc. As it turns out, I had a 5GB image of an XP Pro system, so I copied that over to the evidence locker and fired up Autopsy. I didn't run completely through many of the things that I could have done, because it would take some time to do so...but as far as the things I did try, they worked great.
Don't have an image of your own to play with? Well, the instructions for installing Sleuthkit and Autopsy on Windows also has instructions for how to image a floppy drive...so, you can entertain and amaze your friends by recovering deleted files! Or, you can go to the Digitial Forensics Tool Testing site and grab an image or two to work with.
My hat's off to Brian Carrier, for having created these tools.
Monday, October 24, 2005
Perl for Forensics
Perl is freely available, and Perl scripts are essentially open source. Perl is used by forensics products such as The Sleuthkit and ProDiscover. Perl is used in the Metasploit framework. Perl is great for automating repetitive tasks, parsing files...and it's free. Perl runs on Windows, most Unices, the Mac, and a plethora of other platforms.
O'Reilly has a ton of books on Perl...from how to program to how to use Perl for a variety of tasks.
So my question is, how useful would a book on using Perl for forensics be to you? Say, a reference tome that discusses:
O'Reilly has a ton of books on Perl...from how to program to how to use Perl for a variety of tasks.
So my question is, how useful would a book on using Perl for forensics be to you? Say, a reference tome that discusses:
- Collecting live/volatile data using Perl
- Correlating data from multiple sources using Perl
- Analyzing data, or presenting data for analysis
- Analyzing file formats (retrieving metadata, etc.)
Obviously, a book like this should include copies of all code used or mentioned in the book. As ProDiscover uses Perl as it's scripting language, a book such as this should also include a variety of "ProScripts". The book should also include not only the files analyzed in the book, but additional example files that the reader can explore and practice on...perhaps even an image of drive to examine.
Is this a book you'd be interested in? If so, what would you like to see? What topics do you think should be covered? How would you envision such a book, particularly as something that you'd pick up off of a shelf at a bookstore and decide to purchase? What do you see as the market for such a book?
Saturday, October 22, 2005
VMWare Playa
As a user of VMWare, I received an email the other day that mentioned a new, free product called the VMWare Player. This is a free product that allows you to play a single VMWare virtual machine on Windows or Linux (rpm and tar versions available for Linux). Very cool. Want to share tools, and other stuff that you may not have been able to share before? Want to try out Windows or Linux, but didn't want to shell out the almost $200 for VMWare Workstation?
VMWare also provides some pre-built virtual machines for you to download. What good is a player if you don't have something to play? One is a browser appliance, which you can use for safer web surfing.
This was also picked up by TaoSecurity, along with some comments from readers of that blog, and a link to a chart showing differences in functionality between the Player and other VMWare products.
VMWare also provides some pre-built virtual machines for you to download. What good is a player if you don't have something to play? One is a browser appliance, which you can use for safer web surfing.
This was also picked up by TaoSecurity, along with some comments from readers of that blog, and a link to a chart showing differences in functionality between the Player and other VMWare products.
Word metadata code posted
All,
I've posted the code that I mentioned in my previous post on Word metadata. This code produces the output seen in the blog entry.
The code is commented, including how to obtain the necessary modules if you're using ActiveState Perl. The PPM commands look like this:
ppm install OLE-Storage
ppm install Startup
ppm install Unicode-Map
Give the code a shot, and let me know what you think. As I said in my earlier post, I'm working on producing a standalone EXE via Perl2Exe, for Windows users.
I've posted the code that I mentioned in my previous post on Word metadata. This code produces the output seen in the blog entry.
The code is commented, including how to obtain the necessary modules if you're using ActiveState Perl. The PPM commands look like this:
ppm install OLE-Storage
ppm install Startup
ppm install Unicode-Map
Give the code a shot, and let me know what you think. As I said in my earlier post, I'm working on producing a standalone EXE via Perl2Exe, for Windows users.
Sunday, October 16, 2005
Yet, even more on Word metadata
While awaiting information on the binary format of shortcut (LNK) files, I decided to try to learn more about structured storage and metadata in Word documents. The best example I've seen of that describes some of the metadata in Word documents is available at the Computerbytesman site, and addresses an issue that Tony Blair's government had a while back. While I was researching my book, Richard Smith was kind enough to share his code for retrieving the last 10 author's for within the Word document with me. Since that time, I've thought about taking another look at the sort of metadata that one can retrieve from within a Word document.
I included a Perl script for retrieving Word metadata with my book. The code is on the CD that accompanies the book, in the code directory for chapter 3. The script is called "meta.pl" and uses the Win32::OLE module to create an instance of Word, and use the API to retrieve metadata. Well, as I've seen with the work that I did on reading Event Log files, the API doesn't always get everything. Also, I've been looking for something a little more platform-independant.
Thanks to Richard Smith, I dug into the OLE::Storage module a bit, and found exactly what I was looking for. First, a quick caveat...the POD for this module, as well as some of the supporting modules, is a bit out of date. However, by using some of the accompanying examples (such as ldat, written by Martin Schwartz, copyright '96-'97) and simply trying some things out, I was able to figure things out. So the script uses that module, and a couple of others...but only after it opens the file in binary mode to retrieve other information from the file.
Okay, on to the output. I started with the Blair document from the Computerbytesman site, and got the same information (I didn't include the VBA Macro information, though). I downloaded a couple of arbitrary Word documents from the Web, via Google, and found some interesting info:
--------------------
Statistics
--------------------
File = d:\cd\wd\04_007.doc
Size = 322560 bytes
Magic = 0xa5ec (Word 8.0)
Version = 193
LangID = English (US)
Document has picture(s).
Document was created on Windows.
Magic Created : MS Word 97
Magic Revised : MS Word 97
--------------------
Last Author(s) Info
--------------------
1 : Susan and Shawn Sutherland :
2 : Susan and Shawn Sutherland :
3 : Susan and Shawn Sutherland :
4 : Susan and Shawn Sutherland :
5 : picketb :
6 : padilld :
7 : ONR :
8 : John T. McCain :
9 : horvats :
10 : arbaizd :
--------------------
Summary Information
--------------------
Title : I
Subject :
Authress : PICKETB
LastAuth : arbaizd
RevNum : 2
AppName : Microsoft Word 10.0
Created : 08.12.2003, 16:11:00
Last Saved : 08.12.2003, 16:11:00
Last Printed : 08.12.2003, 16:11:00
--------------------
Document Summary Information
--------------------
Organization : Office of Naval Research
Pretty cool, eh? Again, I found this document on the web. From my previous post, I asked some folks to send me documents written on the Mac platform, and I received a couple. Here's what the output looks like:
--------------------
Statistics
--------------------
File = d:\cd\wd\ex1.doc
Size = 21504 bytes
Magic = 0xa5ec (Word 8.0)
Version = 193
LangID = English (US)
Document was created on a Mac.
File was last saved on a Mac.
Magic Created : Word 98 Mac
Magic Revised : Word 98 Mac
--------------------
Last Author(s) Info
--------------------
1 :
--------------------
Summary Information
--------------------
Title : The quick brown fox jumps over the lazy dog
Subject :
Authress : name
LastAuth : name
RevNum : 1
AppName : Microsoft Word 10.1
Created : 12.10.2005, 02:51:00
Last Saved : 12.10.2005, 02:58:00
Last Printed :
--------------------
Document Summary Information
--------------------
Organization :
Okay, I made a couple of obvious changes, but the point is that there is information within the binary contents of the file information block (FIB) that tells you the platform that a document was created on...for example, if it was created on a Mac, or on a Windows platform. Pretty cool, eh?
So...what do you think? I'll be posting the script soon, along with a couple of other scripts...for example, I'm going to include one that I used for troubleshooting, which simply writes all of the structured storage streams to files on the system. After all, MS describes structured storage as "a file system within a file", so wouldn't you like to see the contents of each of those files? I'm not entirely sure of the usefulness of this with regards to forensic analysis, but someone might find it useful.
An offshoot of all this involves the MergeStreams application (here's something I found at UTulsa) that I've used in some of my presentations. This application allows you to merge an Excel spreadsheet into a Word document, resulting in a much larger, but otherwise unchanged Word doc. However, if you change the resulting file's extension to ".xls", and double-click on it, you'll see the entire, unmodified contents of the spreadsheet. This is due to the streams being merged, and handled by the appropriate application (no, this is not steganography!!). Whenever I've presented on this, I've been asked how this sort of thing can be detected, and up until now, the only solutions I've been able to come up with have include the use of 'strings' and 'find'. With this module, however, you can dump the names of the streams from an OLE document, and if you see a stream named "Workbook" inside a Word document, you can be pretty sure that you've got an embedded document. This is a more accurate method than using 'strings'.
I'll be releasing the scripts soon...there are a couple of things I need to clean up, and I'm having a small issue with the compiled EXE version of the main script (above) that I'm trying to clear up.
I included a Perl script for retrieving Word metadata with my book. The code is on the CD that accompanies the book, in the code directory for chapter 3. The script is called "meta.pl" and uses the Win32::OLE module to create an instance of Word, and use the API to retrieve metadata. Well, as I've seen with the work that I did on reading Event Log files, the API doesn't always get everything. Also, I've been looking for something a little more platform-independant.
Thanks to Richard Smith, I dug into the OLE::Storage module a bit, and found exactly what I was looking for. First, a quick caveat...the POD for this module, as well as some of the supporting modules, is a bit out of date. However, by using some of the accompanying examples (such as ldat, written by Martin Schwartz, copyright '96-'97) and simply trying some things out, I was able to figure things out. So the script uses that module, and a couple of others...but only after it opens the file in binary mode to retrieve other information from the file.
Okay, on to the output. I started with the Blair document from the Computerbytesman site, and got the same information (I didn't include the VBA Macro information, though). I downloaded a couple of arbitrary Word documents from the Web, via Google, and found some interesting info:
--------------------
Statistics
--------------------
File = d:\cd\wd\04_007.doc
Size = 322560 bytes
Magic = 0xa5ec (Word 8.0)
Version = 193
LangID = English (US)
Document has picture(s).
Document was created on Windows.
Magic Created : MS Word 97
Magic Revised : MS Word 97
--------------------
Last Author(s) Info
--------------------
1 : Susan and Shawn Sutherland :
2 : Susan and Shawn Sutherland :
3 : Susan and Shawn Sutherland :
4 : Susan and Shawn Sutherland :
5 : picketb :
6 : padilld :
7 : ONR :
8 : John T. McCain :
9 : horvats :
10 : arbaizd :
--------------------
Summary Information
--------------------
Title : I
Subject :
Authress : PICKETB
LastAuth : arbaizd
RevNum : 2
AppName : Microsoft Word 10.0
Created : 08.12.2003, 16:11:00
Last Saved : 08.12.2003, 16:11:00
Last Printed : 08.12.2003, 16:11:00
--------------------
Document Summary Information
--------------------
Organization : Office of Naval Research
Pretty cool, eh? Again, I found this document on the web. From my previous post, I asked some folks to send me documents written on the Mac platform, and I received a couple. Here's what the output looks like:
--------------------
Statistics
--------------------
File = d:\cd\wd\ex1.doc
Size = 21504 bytes
Magic = 0xa5ec (Word 8.0)
Version = 193
LangID = English (US)
Document was created on a Mac.
File was last saved on a Mac.
Magic Created : Word 98 Mac
Magic Revised : Word 98 Mac
--------------------
Last Author(s) Info
--------------------
1 :
--------------------
Summary Information
--------------------
Title : The quick brown fox jumps over the lazy dog
Subject :
Authress : name
LastAuth : name
RevNum : 1
AppName : Microsoft Word 10.1
Created : 12.10.2005, 02:51:00
Last Saved : 12.10.2005, 02:58:00
Last Printed :
--------------------
Document Summary Information
--------------------
Organization :
Okay, I made a couple of obvious changes, but the point is that there is information within the binary contents of the file information block (FIB) that tells you the platform that a document was created on...for example, if it was created on a Mac, or on a Windows platform. Pretty cool, eh?
So...what do you think? I'll be posting the script soon, along with a couple of other scripts...for example, I'm going to include one that I used for troubleshooting, which simply writes all of the structured storage streams to files on the system. After all, MS describes structured storage as "a file system within a file", so wouldn't you like to see the contents of each of those files? I'm not entirely sure of the usefulness of this with regards to forensic analysis, but someone might find it useful.
An offshoot of all this involves the MergeStreams application (here's something I found at UTulsa) that I've used in some of my presentations. This application allows you to merge an Excel spreadsheet into a Word document, resulting in a much larger, but otherwise unchanged Word doc. However, if you change the resulting file's extension to ".xls", and double-click on it, you'll see the entire, unmodified contents of the spreadsheet. This is due to the streams being merged, and handled by the appropriate application (no, this is not steganography!!). Whenever I've presented on this, I've been asked how this sort of thing can be detected, and up until now, the only solutions I've been able to come up with have include the use of 'strings' and 'find'. With this module, however, you can dump the names of the streams from an OLE document, and if you see a stream named "Workbook" inside a Word document, you can be pretty sure that you've got an embedded document. This is a more accurate method than using 'strings'.
I'll be releasing the scripts soon...there are a couple of things I need to clean up, and I'm having a small issue with the compiled EXE version of the main script (above) that I'm trying to clear up.
Subscribe to:
Posts (Atom)