Links and News

There have been some exciting developments recently on the Windows digital forensic analysis front, and I thought it would be a good idea to bring them all together in one place.

Recover CMD sessions from the pagefile
If you perform analysis of Windows systems at all, be sure to check out Robert's blog post that discusses how to use page_brute (which I'd mentioned previously here) to recover command prompt sessions from the Windows pagefile.  In the post, the author mentions quite correctly that grabbing a memory image still isn't something that's part of standard incident response procedures.  If you receive a laptop system (or an image thereof) you may find a hibernation file, which you can then analyze, if doing so is something that will help you attain your goals.

Page_brute is based on Yara rules, and Robert shares the rule that he wrote...if you look at it, and follow his reasoning in the post, it's amazingly simple AND it works!

This sort of analysis can be very valuable, particularly if you don't have a memory dump available.  As we learned at OMFW 2013, Volatility is moving in the direction of incorporating the pagefile into analysis, which is fantastic...but that's predicated by the responder's ability to capture a memory dump prior to shutting the system down.

I got yara-python installed (with some help...thanks!) and I then extracted the pagefile from an image I have available.  I had also copied the rule out of Robert's blog post, and pasted it into the default_signatures.yar file that is part of page_brute, and ran the script.  In fact, page_brute.py worked so well, that as it was running through the pagefile and extracting artifacts, MS Security Essentials "woke up" and quarantined several extracted blocks identified as Exploit:js/Blacole, specifically KU and MX variants.  I then opened a couple of the output files from the CMDscan_Optimistic_Blanklines folder, and I wasn't seeing any of the output that Robert showed in his blog post, at least not in the first couple of files.  So, I ran strings across the output files, using the following command:

D:\Tools>strings -n 5 H:\test\output\CMDscan_Optimistic_Blanklines\*.page | find "[Version"

I didn't get anything, so I ran the command again, this time without the "[", and I got a number of strings that looked like Registry key paths.  In the end, this took some setup, downloading a script and running two commands, but you know what...even with that amount of effort, I still got 'stuff' that I would not have gotten as quickly.  Not only has page_brute.py proved to be very useful, it also illustrates what can be done when someone wants to get a job done.

Resources
Excellent Yara post; look here to get the user manual and see how to write rules.

Registry Forensics Class
If you're interested in an online course in analyzing the Windows Registry, Andrew Case, Vico Marziale, and Joe Sylve put together the Registry Analysis Master Class over at The Hacker Academy.  If you're interested in the course, take a look at Ken Pryor's review of the class to see if this is something for you.

Windows Application Experience and Compatibility
Corey's got a new blog post up where he discusses the Windows Application Experience and Compatibility feature, and how the RecentFileCache.bcf file can serve as a data source indicating program execution.  As usual, Corey's post is thorough, referencing and building on previous work.

Corey shared a link to his blog post over on the Win4n6 Yahoo group, and Yogesh responded that he's doing some research along the same lines, as well, with a specific focus on Windows 8 and the AmCache.hve file, which follows the same file format as Windows Registry hives.  Yogesh's blog post regarding the AmCache.hve file can be found here.  Why should you care about this file?  Well, from the post:

This file stores information about recently run applications/programs. Some of the information found here includes Executable full path, File timestamps (Last Modified and Created), File SHA1 hash, PE Linker Timestamp, some PE header data and File Version information (from Resource section) such as FileVersion, ProductName, CompanyName and Description.

This information can be very valuable during analysis; for example, using the SHA-1 hash, an analyst could search VirusTotal for information regarding a suspicious file.  The file reference number from the key name could possibly be used to locate other files that may have been written to the system around the same time.

More Stuff
As I was working on a RegRipper plugin for parsing and presenting the data in the AmCache.hve file, I ran across something interesting, albeit the fact that I have only one sample file to look at, at the moment.  Beneath the Root key is a Programs subkey, and that appears to contain subkeys for various programs.  The values within each of these subkeys do not appear to correspond to what Yogesh describes in his post, but there are some very interesting value data available.  For example, the Files value is a multi-string value that appears to reference various files beneath the Root\Files subkey (as described in Yogesh's post) that may be modules loaded by the program.  This can provide for some very interesting correlation, particularly if it's necessary for your analysis.

Yogesh has been posting some great information over on his blog recently, specifically with respect to Registry and Windows Event Log artifacts associated with USB devices connected to Windows 8 systems.  Be sure to add it to your daily reading, or to your blog roll, in order to catch updates.

Sniper Forensics, Memory Analysis, and Malware Detection

I conducted some analysis recently where I used timeline analysis, Volatility, and the Sniper Forensics concepts shared by Chris Pogue to develop a thorough set of findings in relatively short order.

I was analyzing an image acquired from a system thought to have been infected with Poison Ivy.  All I had to go on were IPS alerts of network traffic originating from this system on certain dates...but I had no way to determine how "close" the clocks were for the system and the monitoring device.

I started by creating a timeline, and looking for the use of publicly documented persistence mechanisms employed by the malware in question (Windows service, StubPath values within "Installed Components" Registry keys, etc.), as well as looking for the use of NTFS alternate data streams.  All of these turned up...nothing.  A quick review of the timeline showed me that McAfee AV was installed on the system, so I mounted the image via FTK Imager and scanned it with ClamWin 0.98 and MS Security Essentials (both of which were updated immediately prior to the scan).  MSSE got a hit on a file in the system32 folder, which later turned out to be the initial installer.  I searched the timeline, as well as the Software and System Registry hives for the file name, and got no hits beyond just the existence of that file within the file system.

The system was a laptop system and had a hibernation file, which was last modified the day that the system itself had been shut down.  I exported the hibernation file for analysis, and then downloaded the Win32 standalone version of Volatility version 2.3.1, and used that to convert the hibernation file to raw format, then identify the profile (via the imageinfo plugin) and get a process list (via the pstree plugin).

I got in touch with Jamie Levy (@gleeda), who pointed me to this post, which was extremely helpful.  Based on the output of the malfind plugin, I was able to identify a possible process of interest, and I searched the timeline for the executable file name, only to find nothing.  However, I did have a process ID to correlate to the output of the pstree plugin, and I could see that the process in question was a child of services.exe, which told me not only where to look, but also that the installation process required at least Administrator-level privileges.  Correlating information between the RegRipper samparse.pl and profilelist.pl plugins, I was able to see which user profiles (both local and domain) on the system were members of the appropriate group.  This also provided me with the start time for both processes, which correlated to the system being started.

A fellow team member had suggested running strings across the memory dump, and then searching the output for specific items; doing so, I found what appeared to be the configuration information used by Poison Ivy (which was later confirmed via malware RE performed by another team member).  As a refinement to that approach, I ran the Volatility vaddump plugin, targeting the specific process, and dumped all of the output files to a folder.  I then ran strings across all of the output folders, and found a similar list of items as when I'd run strings across the entire memory dump.

I validated the configuration item findings via the Volatility handles plugin, looking for mutants within the specific process.  I also dumped the process executable from the memory dump via the procmemdump plugin; the first time I did it, MSSE lit up and quarantined the file, so I disabled MSSE and re-ran the plugin (I set my command prompts with QuickEdit and Insert modes, so re-running the command line as as simple as hitting the up-arrow once, and then hitting Enter...).  I was able to ship the dumped PE file and the initial wrapper I found to a specialist for analysis while I continued my analysis.

I then ran the svcscan plugin and searched the output for the executable file name, and found the Windows service settings, to include the service name.  I also ran the dlllist plugin to see if there were any DLLs that I might be interested in extracting from the image.

I also ran the netscan plugin, and reviewing the output gave no indication of network connections associated with the process in question.  Had there been a connection established associated with the process of interest, I would've run Jamaal's ethscan module, which he talked about (however briefly) at the recent OMFW.

I had downloaded the Poison Ivy plugin, which according to the headers, is specific to one version of the PIvy server.   The plugin ran for quite a while, and because I had what I needed, I simply halted it before it completed.

Timing
Something important to point out here is that the analysis that I've described here did not take days or weeks to complete; rather, the research and memory analysis was all completed in just a few hours on one evening.  It could have gone a bit quicker, but until recently, I haven't had an opportunity to do a lot of this type of analysis.  However, incorporating a "Sniper Forensics" thought process into my analysis, and in turn making the best use of available tools and processes, allowed me develop findings in an efficient and thorough manner.

In short, the process (with Volatility plugins) looks like this:
- convert, imageinfo, pstree
- malfind - get PID
- run vaddump against the PID, then run strings against the output
- run handles against the PID
- run procmemdump against the PID (after disabling AV)
- run dlllist against the PID
- run netscan; if connections are found associated with the PID, run ethscan

At this point, I had a good deal of information that I could add to my timeline in order to provide additional context, granularity, and relative confidence in the data I was viewing.  File system metadata can be easily modified, but Windows Event Log records indicating service installation and service start can be correlated with process start times, assisting you in overcoming challenges imposed by the use of anti-forensics techniques.

It's also important to point out that Registry, timeline, and memory analysis are all tools, and while they're all useful, each of them in isolation is nowhere near as powerful as using them all together.  Each technique can provide insight that can either augment or be used as pivot points for another.

Resources
A couple of interesting items have popped up recently regarding memory acquisition and analysis, and I thought it would be a good idea to provide them here:

• Jamie also pointed me to this post, which, while it wasn't directly helpful (the image I was working with was from a Win7SP1 system), it does show the thought process and work flow in solving the challenge
• From MoonSols, some new features in DumpIt
• Mark Baggett's ISC Diary posts on winpmem and its uses: here, and here
• Page_brute - check out how you can incorporate the pagefile into your analysis, until Volatility v3 hits the streets

Tools, Malware, and more conference follow-up

Tools
Arsenal Recon - Image Mounter utility: the web site says that the tool is "currently geared towards digital forensics and incident response developers, but we have released a sample GUI and command line mount/management utility known as "MountTool" as a proof of concept."

The web site goes on to say, "We have heard that others in the DFIR community are already building better GUIs and extending the functionality of Arsenal Image Mounter..."; this is great to hear, and I hope that this is something that becomes public.  Having a proof of concept tool is great to test things out, but seeing something that extends the capabilities of the utility is even better, and I think, far more useful.

Willi Ballenthin's EVXTract: Here is Willi's presentation from the SANS Summit in Prague, on 6 Oct 2013.  In the sixth slide, Willi mentions the 6 steps to carving EVT records from unallocated space or other unstructured data.  Somewhere in there, perhaps step 4a, should be "given the record size, read that number of bytes into the buffer, and the last 4 bytes should be the same as the first four bytes".  This is the "sanity check" I've used as an initial step for validating EVT records.

Anyway, what Willi's presentation and materials really demonstrate for me is the move to carving for records rather than full files.  Yes, others have been doing this for a while, in particular the MagnetForensics folks with their IEF product, but that's not an open source tool.  Understanding data structures and going after the individual records can be far more fruitful than going after full files.

Mari has written up an excellent post detailing how to retrieve deleted data from a SQLite database; she's even provided a Python-based parser.  This is yet another aspect of data retrieval that is based on a detailed knowledge and understanding of data structures, similar to what was discussed here (IE index.dat deleted records), and here (MFT resident file residue).

Lance's post regarding the tools he turns to during examinations, broken down by tiers.  His list is very useful in that it illustrates a thought process that others can look at for comparison.  I can't say that I have a similar breakdown, which probably has more to do with the types of analysis I tend to get engaged in, and the prior information that each of us may have available.

Of course, how a tool is used can also be very valuable information.  For example, from Lance's post, as

well as what I saw at OSDFC, folks use RegRipper, but apparently not the way I use it.  It seems that the predominant means of using RegRipper is to just run all the plugins against the available hives.  That may be good for some folks, but like Corey Harrell, I tend to take something of a more targeted approach.  Often during my own examinations, I don't need everything...in fact, getting everything can often be an expenditure of time and effort that I can't afford, as I have to sort through a lot of data that isn't particularly useful or beneficial.  While in some instances it is useful to take a broader approach, there are times and circumstances when it's far more beneficial to take something of a targeted approach, if for no other reason to do a quick check and get something of value quickly, leaving the everything for later.  At times, I've found it very beneficial to use a Registry viewer (WRR is pretty good, although it doesn't handle "big data" values) for viewing and searches, then run specific RegRipper plugins, and then have a plugin open in an editor for tweaking.  That's kind of how I went about this work involving shell items.

Based on recent conferences, I'm going to have to look at adding TSK Autopsy  to one of my own tiers.

Malware Response and Analysis
Claus has a new post up regarding his Anti-Malware Response Go Kit; in this case, Claus discusses more about his requirements and process, whereas some of his previous posts have been admittedly valuable lists of tools.  The one correction I would offer up, however, is in the section where he briefly discusses RegRipper: "Plugins are developed by the community..." - actually, not so much, really.  Yes, there are a number of plugins developed by other folks, for which I am very thankful, and offer a huge thanks to them for doing so. Other plugins were developed or extended because someone (Corey Harrell) saw the need and reached out to me, but for the most part, the majority of the development of plugins have not been something that's sought after by the community at large.  I have updated a couple of plugins (appcompatcache.pl) to support Windows 8/8.1 thanks to the suggestion and submission of additional test data by Eric Z.  Also, I've written a number of malware-specific, "tactical" plugins based on something I've seen, usually within just a couple of minutes of reading the material...but again, these are not something that have been requested or sought by the community.

From the Handler's Diary blog, Analyzing Malicious Processes: very cool use case for Volatility.  Not only does the post illustrate how to use Volatility, but it also clearly illustrates what an artifact (in this case, of lateral movement) "looks like", which is something that we often don't see addressed.  Even though artifacts are mentioned, many times, there's very little information about what to look for on disk or in memory with respect to those artifacts.

Also from the Handler's Diary - jackcr's DFIR challenge summary; Jamie Levy (@gleeda) referred to this challenge in her "Every Step You Take: Profiling the System" talk at OMFW2013.

From Lenny Zeltser, a list of XOR obfuscation examination tools.

Win32/Trooti is an example of malware that "parks" on a vacant SvcHost value.  [TrendMicro, M86 Security]  It's interesting how the different write-ups address the particular value on which the malware "parks"...some tell us that it happens, others share the results of their particular analysis.  More than anything else, I think that this information can help us in reviewing and if necessary, updating our own malware detection techniques.

Conference Followup
There's another write up available regarding recent conferences, in this case, the same ones I was able to attend.  As such, the write-up provides something of a different perspective.  You can find the OMFW & OSDFC Recap post over at the HiddenIllusion blog site.  This post is more of a blow-by-blow of the conferences, and it does give an interesting perspective on the conferences.  A couple of things I wanted to comment on (and this doesn't mean that I disagree...):

From the general notes: "I was told that my tweets and recap post of last years activities was helpful to those who couldn't attend..." - this is much more of a truism than most really recognize, I think.  Not everyone can attend conferences, but very often we're able to learn more about which conferences or events would be most beneficial to us by what others share about their experiences; what was good, what wasn't so good, what there should be more or less of, etc.  This sort of feedback can not only be valuable to folks who are planning out their conference attendance, but it can also be extremely valuable to conference organizers and presenters, as well.  For example, in the OSDFC section, there was this quote:

On the disappointing side - I did feel like I was seeing a noticeable amount of people doing the same things as others have already done.

That's extremely valuable to know.  Yes, you're right...there was content that would make folks think, "wow, I've seen this stuff before", and there could be any number of reasons for that.  Sometimes, I think folks pursue something because they're seeing it for the first time, and they don't do a comprehensive literature search prior to kicking off their research.  Sometimes, this is good, because it's done for educational purposes, and the researcher may find something new.  Remember though...this year, the conference program was crowd-sourced, so it wasn't Brian and the BasisTech staff who decided which presentations would be given.

Under the "Memoirs of a Hidsight[sic] Hero" section, the author says, "Don't try and write a book about Mac rootkits..."; it wasn't so much that Cem was out to disprove the authors because they were writing a book.  Rather, my take was that Cem heard the claims of near-complete anonymity and thought, "that can't be right", and ended up disproving the claims.  Maybe the take away from this one would be, "...if you're going to write a book on Mac rootkits, get Cem as a co-author or tech editor."  ;-)

With respect to the MantaRay presentation: "...maybe useful for others but doesn't fit into my process flow." This is exactly right...depending upon the types of issues you face, you may not need to run every tool every time.  However, one of the useful things about tools like MantaRay and it's predecessor, TapeWorm, is that very often, they're configurable.  That is, you can trim them down or add to them in order to meet your needs.  The guys who developed MantaRay have provided the tools for use by others, which is great, particularly for folks with similar use-cases, or those new to the issue at hand.

Conferences

I recently had the opportunity (and honor) of attending the Open Memory Forensics Workshop (OMFW) and the Open Source Digital Forensics Conference (#OSDFCon), held in Chantilly, VA.  I've attended both conferences in the past, had a great time, and this time around was no different.

OMFW
I've always enjoyed the format that Aaron has used for the OMFW, going back to the very first one.  That first time, there was a short presentation followed by a panel, and back and forth, with breaks.  It was fast-moving, the important stuff was shared, and if you wanted more information, there was usually a web site that you could visit in order to download the tools, etc.

This time around, there was greater focus on things like upcoming updates to Volatility, and the creation of the Volatility Foundation.  Also, a presentation by George M. Garner, Jr., was added, so there were more speakers, more variety in topics discussed, and a faster pace, all of which worked out well.

The presentations that I really got the most out of were those that were more akin to use cases.

Sean and Steven did a great job showing how they'd used various Volatility plugins and techniques to get ahead of the bad guys during an engagement, by moving faster than the bad guys could react and getting inside their OODA loop.

Cem's presentation was pretty fascinating, in that it all seemed to have started with a claim by someone that they could hide via a rootkit on Mac OSX systems.  Cem's very unassuming, and disproved the claim pretty conclusively, apparently derailing a book (or at least a chapter of the book) in the process!

Jamie's presentation involved leveraging CybOX with Volatility, and was very interesting, as well as well-received.

There was more build-up and hype to Jamaal's presentation than there was actual presentation!  ;-)  But that doesn't take anything at all from what Jamaal talked about...he'd developed a plugin called ethscan that will scan a memory dump (Windows, Linux, Mac) and produce a pcap.  Jamaal pointed out quite correctly that many times when responding to an incident, you won't have access to a pcap file from the incident; however, it's possible that you can pull the information you need out of the memory buffer from the system(s) involved.

What's really great about OMFW is that not only does Aaron get some of the big names that are really working hard (thanks to them!) to push the envelope in this area of study to present, but there are also a lot of great talks in a very short time period.  I'll admit that I wasn't really interested in what goes into the framework itself (that's more for the developers), but there were presentations on Android and Linux memory analysis; there's something for everyone.  You may not be interested in one presentation, but wait a few minutes...someone will talk about a plugin or a process, and you'll be glued to what they're saying.

Swag this year was a cool coffee mug and Volatility stickers.

Here's a wrap-up from last year's conference.  You can keep up on new developments in Volatility, as well as the Volatility training schedule, at the Volatility Labs blog.

OSDFCon
I've attended this conference before, and just as in the past, there is a lot of great information shared, with something for everyone.  Personally, I'm more interested in the talks that present how a practitioner used open source tools to accomplish something, solve a problem, or overcome a challenge.  I'm not so much interested in academic presentations, nor so much in talks that talk about open source tools that folks have developed.  As in the past, I'd suggest yet again that there be multiple tracks for this conference...one for academics and developers, and another for practitioners, by practitioners.

As part of full disclosure, I did not attend any of the training or tutorials, and I could not attend all of the presentations.

You can see the program of talks here.

Thoughts and Take Aways
Visualization in DFIR is a sticky point...in some ways, it may be a solution without a problem.  Okay, so the recommendation is, "don't use pie charts"...got it.  But how does one use visualization techniques to perform analysis, when malware and intrusions follow the Least Frequency of Occurrence?  How can a histogram show an analyst when the bad guy or the malware compromised a system when activities such as normal user activity, software and system updates, etc., are the overwhelming available activity?  Maybe there is a way to take a bite out of this, but I'm not sure that academics can really start to address this until there is a crossover into the practitioner's end of the pool.  I only mention this because it's a recurring thought that I have each time I attend this conference.

As Simson pointed out, much of the current visualization occurs after the analyst has completed their examination and is preparing a report, either for a customer or for presentation in court.  Maybe that's just the nature of the beast.

Swag this year was a plastic coffee cup for the car with the TSK logo, TSK stickers, and a DVD of Autopsy.

Resources
Link to Kristinn's stuff

Thanks
We should all give a great, big Thank You to everyone involved in making both of these conferences possible.  It takes a lot of work to organize a conference...I can only imagine that it's right up there with herding cats down a beach...and providing a forum to bring folks together.  So, to the organizers and presenters, to everyone who worked so hard on making these conferences possible, to those who sat at tables to provide clues to the clueless ("...where's the bathroom?")...thank you.

What else
There is another thing that I really like about DFIR-related conferences; interacting with other DFIR folks that I don't get to see very often, and even those who are not directly involved with what we do on a day-to-day basis.  Unfortunately, it seems that few folks who attend these conferences want to engage and talk about DFIR topics, but now and again I find someone who does.

In this case, a good friend of mine wanted to discuss "...is what we do a 'science' or an 'art'?" at lunch.  And when I say "discuss", I don't mean stand around and listen to others, I mean actively engaging in discussion.  That's what a small group of us...there were only four of us at the table...did during lunch on Tuesday.  Many times, finding DFIR folks at DFIR conferences that want to actively engage in discussion and sharing of DFIR topics...new malware autostart/persistence mechanisms seen, new/novel uses of tools, etc...is hard to do.  I've been to conferences before where, for whatever reason, you just can't find anyone to discuss anything related to DFIR, or to what they do.  In this instance, that wasn't the case, and some fascinating discussion ensued.

Links

This is not the persistence mechanism you were looking for...
First off, thanks to David Cowen for taking the time to address a question regarding the use of the SvcHost key in the Software hive as a persistence mechanism.

It all started with a response to one of David's Sunday Funday challenges, where the SvcHost key was held out as a persistence mechanism in and of itself.  This got me to thinking because it wasn't something I was familiar with, based on my own research...so I wanted to know more and posted a question.  David took it on as an exercise for himself, and posted his findings.  Thanks to Dave to doing the work and sharing his findings with the community.

The purpose of this isn't to prove someone wrong...not at all.  Rather, it is to challenge popularly-held beliefs about DFIR artifacts and ask, is this correct?  Very often, something we've read or heard persists (no pun intended) long enough that it becomes accepted as fact.  One example that I see time and time again is malware that creates persistence in the HKCU\..\Run key, and the report stating that the malware does this to start again when the system boots.  This simply isn't the case, but it's stated on the Microsoft MMPC site, as well as by other malware analysts, often enough that it's simply accepted as "fact".

Interesting Reading
I saw that Corey Harrell linked to a couple of interesting articles on Twitter, one being a report indicating that security professionals in enterprise environments lack malware detection skills.  If you follow the links to the report, you'll see that its based on a survey; even so, I think that as a responder, it correlates pretty closely to my experience, as well as that of others who've responded to incidents such as these, either as a consultant or as an FTE.  The report lists three "root causes for the "darkness"", but I would suggest that they missed the most important one...management.  Folks in the IT industry focus on where their management tells them to focus, and well as what management supports.  If management focus is to keep email up and running, that's where IT will focus.  If management sends IT staff off to training, but there's no requirement to use any of that training when they return, the new skills atrophy.

I have a couple of posts that may be of use to folks, most of which are linked via this one.  Also, WFA 3/e (and the upcoming 4/e) has an entire chapter that covers this material, as well.  Also, be sure to read Corey's blog post on malware root cause analysis, which provides a great deal of valuable information, as well as his Triaging Malware Incidents post.

The other article points to a new post-exploitation wiki that is available from the folks at the NoVA InfoSec group.  This effort appears to be getting up and running, but it is a pretty cool idea to take a great deal of the knowledge and experience in responder's heads and post it in a way that it can be shared with others.  This is definitely a site to keep an eye on.

Malware Persistence
While we're on the topic of malware, I ran across this very interesting write-up on the Terminator RAT.  What I found most fascinating about the malware is the persistence mechanism; specifically, the malware 'sits' in a user's Startup folder, but can modify the Registry to redirect where that Startup folder is within the file system.  That is, it can "tell" the OS to use another folder besides the user's Start Menu\Programs\StartUp folder.  After reading this write-up, it took me only about 6 minutes to write a RegRipper plugin to extract this information, so now I can automatically search for this item.  It didn't take too much more to add a check to the plugin, so that if the path is anything other than what is expected, the plugin will flag it for me.  Interestingly, this is one of the suggested locations to look based on Symantec's list of common Registry key locations used by malware.

That's not the only interesting persistence mechanism I've seen recently; I ran across a description of Win32/KanKan not too long ago and wrote up a RegRipper plugin to help detect anomalies in under 20 minutes.

Tools
Lance recently posted on tools he uses during exams; it's a great list, and probably indicative of what many DFIR folks use.  I hadn't really thought about it before.

I don't have the tier 1 tools that Lance has, so my list is a bit different.  More often than not, I've found that the tiers of tools that I use depends heavily on the goals of the examination...I base my analysis process on what I'm asked to show, demonstrate or discover.  For example, I've had analysis engagements where the goal was to answer questions based on the Windows XP/2003 Event Logs, which had been cleared.  As such, my tier 1 tools become mmls.exe and blkls.exe from the TSK tools, strings from MS, and Perl.  In one case, I was able to retrieve over 330 event records, to include the "smoking gun", but in another case, I found over 73K valid event records, none of which was the one I was looking for (parsing the Security hive with the RegRipper auditpol.pl plugin showed me why this was the case).

In a more general sense, I usually start off using FTK Imager for image verification.  Like Lance, I use LogParser, great tool from MS for extracting records from Windows Event Logs, and it's useful for a number of other things, as well.

Also like Lance, I write a lot of my own tools and utilities in Perl, or add to ones that I already have (RegRipper, etc.).  Some of the code that I use isn't so much full tools but subroutines and functions that I can cut-and-paste into other tools, such as a function that I have for dumping binary data in hex editor-format.

Windows 8 Forensics
I've been working on updating WFA to the fourth edition, and as such, I've been attempting to address for DFIR analysts the recurring question of "...what's new that we need to know in Windows ___?" (insert whichever version, starting with XP...).  I thought I'd post a bunch of the links I've found to be very useful in helping to answer that question.  Here are the links I've found recently:

Amanda Thompson's Windows 8 Forensic Guide

Ken Johnson's SANS DFIR Summit 2012 presentation: Windows 8 Recovery Forensics

ForensicsWiki: Prefetch - the page links to research conducted by Jared Atkinson and Yogesh Kahtri, both of whom have documented changes in the Windows 8 .pf file format.

Digital Forensics Stream: Windows 8 and 8.1 Search Charm History

Windows 8 Forensics: Recycle Bin

CyberArms: Windows 8 Forensics: Internet History Cache; also, David Cowen posted the answer to his blog challenge regarding how to analyze the IE10 web history database.

Shell Item Artifacts, Reloaded

I spoke on David Cowen and crew's Forensic Lunch a bit ago, on the topic of shell item artifacts.  I put together some slides at the last moment to use as visual references for the discussion, to illustrate what I'd done with respect to digging into the talk a bit more.  The slides

In short, what I'd done is this...based on a previous Forensic Lunch, during which Joachim Metz discussed the existence of MFT file reference numbers within some of the shell item structures.  Specifically, starting with Vista, shell items pointing to files and folders appear to contain MFT file reference numbers.  This is mentioned not only in Joachim's Windows Shell Item format specification, but it's also described on Willi Ballenthin's Shellbags analysis page.

Accepting this, I wanted to validate the information and see what it looks like in the real world.  Using FTK Imager Lite, I extracted the MFT and USRCLASS.DAT hive file from my own Windows 7 system.  Parsing the shellbags entries from the USRCLASS.DAT hive (using a customized RegRipper plugin), I was able to get a hex dump of specific shell items as all of the shellbags were being parsed.  I redirected the output of the plugin to a file, and selected specific entries for analysis.  Figure 1 illustrates one of those examples.

Fig. 1: Sample Shell Item

The example that we're using is for a shell item that points to the D:\cases folder, with the key path Shell\BagMRU\1\2\18.  As you can see in figure 1, I've boxed the DOSDate times in yellow; the MFT file reference number is marked in colored text, with the MFT record entry (i.e., 45) in red, and the sequence number (i.e., 13) in green.  I highlighted these values, as we'll be using them in the rest of our examination.

The translated DOSDate times are as follows:

M: 2011-11-29 20:27:44
A: 2011-11-29 20:27:44
B: 2011-11-29 20:27:44

The times listed above are the last modified, last accessed, and creation/born dates for the folder, extracted and translated from the shell item that points to the folder (see fig. 1).  Per Joachim's format specification, there doesn't seem to be an entry modified time value available.  All of the times are listed in UTC format.

It's important to keep in mind where these times come from...the time stamps are read from the MFT (in FILETIME format) and translated to DOSDate time stamps via the FileTimeToDosDateTime() function.  

I had also extracted the MFT from the D:\ volume and parsed it via a custom Perl script.  I searched the output for record number 45, and it still had the sequence number of 13.  

The times from the $STANDARD_INFORMATION attribute:

M: Mon Sep 23 16:17:36 2013 Z

A: Mon Sep 23 16:17:36 2013 Z

C: Mon Sep 23 16:17:36 2013 Z

B: Tue Nov 29 20:27:43 2011 Z

The times from the $FILE_NAME attribute:

M: Tue Nov 29 20:27:43 2011 Z

A: Tue Nov 29 20:27:43 2011 Z

C: Tue Nov 29 20:27:43 2011 Z

B: Tue Nov 29 20:27:43 2011 Z

Now, the big question is...so what?  Well, the fact is that this information can be extremely useful to an analyst.

The time stamps can be extremely telling.  In this case, we see that the times from the shell item are relatively close to those within the $FILE_NAME attribute; this tells us that 

Sebastien pointed out something important with respect to shellbags on Windows 7 systems a bit ago over on the Win4n6 Yahoo group, specifically:

"Go in your Windows 7 help file and search for "Folders: frequently asked questions". Then select: "Why doesn't Windows remember a folder window's size and location on the desktop?". You will find why you are not able to find something similar on Win7:

"In Windows Vista, a folder window opens at the same size and location on the desktop that it did the last time you closed it, based on the location where the folder is stored. For example, if you resize the Music folder window and then close it, it'll be the same size the next time you open it.

Windows 7 remembers one size and location setting for all your folders and libraries. So each time you open Windows Explorer, it'll open at the same size and location on the desktop that it did the last time you closed it, regardless of which folder or library you open.""

The MFT file reference number tells us something about the MFT record; specifically, MFT records are reused, not deleted, when a file is deleted, and the sequence number is incremented each time the record is reused.  In our example, the folder still exists, and the MFT file reference number from the shell item points to an existing record in the MFT.  If this wasn't the case...if the sequence number in the MFT was 14 or more, then the information from the shell item would provide us with historical information from the system, showing us what existed on the system at some point in the past.  In this case, the LastWrite time for the key in question (which, based on the MRU values, applies to the item of interest), is 2012-05-22 14:34:27 UTC, which tells us when the folder in question actually existed on the system.  So, in addition to VSCs and hives in the RegBack folder, we have yet another potential source of historical information on systems, and it's simply a matter of how this information will be applied during an investigation.

Where this becomes really valuable, particularly if it pertains to the goals of your exam, is that you can develop a partial reconstruction of what a system "looked like" in the past...it would be more of a smear than a snapshot, given the various sources.  What I mean by that is that shell items exist within many more locations and artifacts on a Windows system than simply the shellbags...as previously mentioned, shell items exist in shortcut/LNK files, Jump Lists (Win7/8), as well as a number of locations within the Registry.  In short, there are a lot of locations within a Windows system where these particular artifacts can be found, and they seem to get more numerous as the versions of Windows increase, and they're created behind the scenes by the operating system.  As such, they're not only useful for seeing that the system "looked like" in the past, but they can also be valuable if the use of anti-forensics techniques are suspected.

Finally, I'm sure that you noticed the slight discrepancy between the times listed in the shell item, and what's in the MFT.  This most likely has to do with the translation that occurs via the API function...a 64-bit value with 100 nanosecond granularity is reduced to a 32-bit value with second granularity.  Also, per the API function, the seconds are divided by 2, and there's no sub-second granularity to the value.

Links - Malware Edition

Malware
Bromium Labs posted some pretty interesting information regarding another Zeus variant; the information in this post is very useful.  For example, the phishing attack(s) reportedly targeted folks in the publishing industry.

What I found most interesting is that the variant, with all of its new capabilities, still uses the Run key for persistence.

Looking at other artifacts that can be used to detect malware on systems, see this Zeus write up from SecureWorks...one of the listed capabilities is that it can modify the hosts file on the system.  MS KB 172218 illustrates why this is important...but it's also something that can be checked with a very quick query.

Speaking of write ups, I really enjoyed reading this one from System Forensics, for a couple of reasons:

First, the author documents the setup so that you can not only see what they're doing, but so that the analysis can be replicated.

Second, the author uses the tools available to document the malware being analyzed.  For example, they use PEView to determine information about the sample, including the fact that it's compiled for 32-bit systems.  This is pretty significant information, particularly when it comes to where one (DF analyst, first responder) will look for artifacts.  Fortunately, the system on which the malware was run is also 32-bit, so analysis will be pretty straightforward.  It does seem very interesting to me that most malware analysts/RE folks appear to use 32-bit Windows XP when they conduct dynamic analysis.

Again, we see that this variant uses the Run key (in this case, in the user context) for persistence.

Finally, they performed Prefetch file analysis to gather some more information regarding what the malware actually does on a system.

A couple of thoughts about the analysis:
Had the author run the malware and then copied off the MFT, they might have recovered the batch files as they're very likely resident files.  Even if the files had been marked as not in use (i.e., deleted), had they responded quickly enough, they might have been able to retrieve the MFT before those records were overwritten.

The author states in the article, "The stolen data is sent via the C&C using the HTTP protocol."; I tend to believe that it can be valuable to know how this is done.  For example, if the WinInet API is used, there may be a set of artifacts available that can assist analysts in gaining some information regarding the malware.

IR
Corey released his Tr3Secure data collection script.  Open the batch file up in Notepad to see what it does...Corey put a lot of work into the script, and apparently got some great input from others in the community - see what happens when you share what you're doing, and someone else actually takes the time to look at it, and comment on it?  Stuff just gets better.

Memory
If you're grabbing memory during IR, you might want to take a look at SketchyMoose's Total Recall script.  Corey's script gives you the capability to dump memory, and SketchyMoose's script can help make analysis a bit easier, as well.

Persistence
Adam has posted another in a series (four total, thus far) of blogs regarding persistence mechanisms.  There is some pretty interesting stuff so far, and I was recently looking at a couple of his posts, in particular #3 in the series.  I tried out some of the things he described under the App Paths section of the post, and I couldn't get them to work.  For example, I tried typing "pbrush" and "pbrush.exe" at the command prompt, and just go the familiar, "'pbrush' is not recognized as an internal or external command, operable program or batch file."  I also added calc.exe as a key name, and for the default value, added the full path to Notepad.exe (in the system32 folder) and tried launching calc.exe...each time, the Calculator would launch.  I have, however, seen the AppCertDlls key reportedly used for persistence in malware write ups, which is why I wrote the RegRipper plugin to retrieve that information.

Update: Per an exchange that I had with Adam via Twitter (good gawd, Twitter is a horrible way to try to either explain things, or get folks to elaborate on something...people, don't use it for that...), apparently, the App Paths "thing" that Adam pointed out only works if you try to run the command via the Run box ("through the shell"), and doesn't work if you try to run it from the command prompt.