Friday, November 13, 2009

Some Analysis Coolness

TimeLine Analysis
The most recent issue of Hakin9 is available second article on timeline creation and analysis is in this one; it's a hands-on walk-through of using the tools I put together, and use on a regular basis. You your own dogfood, as it were.

What do I like so much about this analysis method? Well, it's fast, it's relatively easy, and it lets an analyst (i.e., me) see a bunch of stuff all together in one place. It's pretty cool to see things like a remote login, creation of the PSExecSvc service, see that service start, then see a bunch of other files being include the data files created by the malware.

Another thing I like about timeline creation and analysis is this...let's say you've got an analyst (or a team) on-site working an engagement, and they're stuck with something; determining the avenue of infection or compromise...whatever. Now let's assume that it's an engagement involving sensitive data, and they're trying to scope everything AND do collections. You can have those analysts dump the file system metadata, extract selected files from the system or image, zip all of that up and send it to someone for analysis. Not only do you run your analysis in're not sending that sensitive data out! That's right, can increase your response efficiency and effectiveness using off-site staff, without further exposing sensitive data!

The version of the tools used in the article are available for download from the Win4n6 Yahoo group. The tools are all separate, standalone tools for right now because, to be honest, I don't always use them all together. Sometimes, it's good to see activity in a different others, it's good to see a limited subset of activity (say, just your Event Log records) all at once, before moving on. By having separate tools, the analyst can intelligently select what they want added to the timeline in order to build it out.

File and Document Metadata
When I used to present at LE-oriented conferences more often, I'd talk about a nifty little tool out there called MergeStreams. This is a great little tool that essentially allows you to "hide" an Excel spreadsheet inside a Word document. This only applies to pre-Office 2007 document formats, however. I'll say that only works on versions of MSOffice that use the OLE compound document format. What I'd show is someone pasting pictures (re: illicit images) into a Word document and then merging those with an Excel spreadsheet. Name the file "myspreadsheet.xls" and you would see the Excel spreadsheet. Rename the file, giving it a .doc extension, and you'd see the Word document.

While we're talking about Office document metadata, now is a good time to revisit some tools for extracting metadata; for pre-Office 2007 documents that use the OLE structured storage format, I've used the tools from my book, and quite effectively, and there's OffVis from MS; for Office 2007 documents, try

Didier Stevens has come up with something similar for PDF documents. All I can say about this Really. This takes me back to '99, when I was sitting in the EnCase Introductory Training course in Leesburg, VA, and we were talking about file signature analysis. Gone are the days where we can simply scan for file signatures and compare that to the file order to do a decent job, we now have to go deeper. Just because a file begins with "MZ", is it really a Windows PE file? Is the PDF or Word (pre-2007) document really just a document, or is it a container masking/hiding something else?
Remember, a lot of the anti-forensics techniques out there target the analyst and their training.

Speaking of files, have you seen this new plugin from Bit9 called FileAdvisor? It's apparently a shell plugin for Windows, so if you find a suspicious file on your system, you can right-click it, and hash it and submit it for analysis. To view results, you'll need to register at the site with your name, email address, and a password. I don't necessarily see this on every user's desktop, but I do see responders and analysts possibly having it installed on a system somewhere.

Memory Parsing/Analysis
Jeff Bryner has put together a Python script for extracting FaceBook artifacts from a memory dump called pdfbook. For Windows systems, the script parses memory dumps from pd...I wonder if you could do the same thing using a full memory dump, extracting just the memory used by the process? Jeff has also released yim2text, a Python script for extracting Yahoo chat artifacts. Very cool.

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