Wednesday, March 9, 2011

Timelines with Registry Data

I've posted before about log2timeline, and now I'm going to add to that a bit.

This is about incorporating regripper output into the timeline. SANS teaches about this in FOR508, and I'm going to "streamline" the process a bit. Without SANS (where I learned of the possibilities) and Harlan Carvey (the source of regripper), and coffee this would not be possible.

So here's the situation: I'm working an investigation with several systems, and starting by building timelines. Standard process - fls, l2t, mactime. But before working up the final bodyfiles and running mactime, I'm going to pull in registry data with regripper.

I'm working in my linux system, which is Ubuntu based. Using Lupin's great post here I've incorporated the latest version of regripper into my system.

At first I was going to bash it together with variables, but in the end it seemed like there would be four or five, and I thought that was too much typing across several images. It seemed more efficient to type my command line once, then repeat and modify the couple things I would need.

So my evidence items are numbered sequentially, like XYZ-001, XYZ-002, and so on. Their respective file systems are mounted accordingly on /mnt/001, /mnt/002, ... The drive containing the images is a Truecrypt volume, so it's mounted on /media/truecrypt1. I'm storing my output files in a separate directory for each evidence item, named for the number and custodian, like /media/truecrypt1/001_jones, /media/truecrypt1/002_smith, etc. The bodyfiles I've already created are named like 001.fls, 001.l2t so I can easily tell which is which. My regripper output will continue in that vein with 001.reg.

Now regripper documentation and SANS teach to use it by pathing out to each hive, then redirecting output somewhere. Something like:
# -r /media/sda2/Windows/System32/config/SAM -f sam >> /media/sdb1/evidence/timelines/jones_regripper.txt
Something like that. But that's too much typing for me. And like I said, I thought about scripting it, but there's just too many variables for what needs to be done - source path, source file, module, destination path, destination file, ack pfft!

So to pull a page from my old ways with log2timeline (before timescanner), I did the following, from within my regripper directory:
# find /mnt/001/ -iname system | while read d; do ./ -f all -r "$d" >> /media/truecrypt1/001_jones/001.reg; done
Then all I have to do is replace "system" with "sam" "software" and "ntuser.dat" and that takes care of 001. For 002 I change the "1" to "2", change "jones" to "smith" and I'm good to go. Far quicker than typing all the paths each time, or plugging in several variables. If I wanted to get more creative I probably could script it to run through the various hives for each set of variables, and then just put in the set for the next custodian system. That might be okay, but I didn't feel like going that far today. Now that I think about it, I believe I will tomorrow, though.

This is no command line kung-fu, but I like it; it's better than a bunch of typing anyway. What it does is within the /mnt/001/ directory, it searches for files named "system" with no case-sensitivity. STDOUT is the normal output; this is piped to a while loop that runs against the "system" file (-r). I had some errors trying to use the specific modules (-f) and being lazy (just like not wanting to type) I decided just to try "all." This worked just fine, no more errors. You'll see as it runs that regtime is called; I believe this is what creates the mactime-formatted output.

That takes care of my timeline pieces. Now to get a single bodyfile for each system... Within my output directory (/media/truecrypt1/001_jones):
# cat 001.* >> body.001
I'm now reversing the order, to keep my pieces separated. It helps me track the flow/progress as well, which I'll show next.

I'm trying to identify areas of activity (or inactivity) over several months so that I can focus in on details with a more limited timeframe. To do this I'll be running mactime and building a daily index. For 001, this looks like:

# mactime -d -z CST6CDT -m -y -b /media/truecrypt1/001_jones/body.001 2010-01-30..2010-05-24 -i day >> /media/truecrypt1/001_jones/index.001
This is just wrong. Shame on me. Here's how it needs to be:

# mactime -b /media/truecrypt1/001_jones/body.001 -i day /media/truecrypt1/001_jones/index.001 -d -m -y -z CST6CDT 2010-01-30..2010-05-24

This gives me a CSV file (-d) that gives a nice overview of total activity each day during my ~4 month period. Then hopefully I'll be able to focus in on a few specific days that look interesting (maybe a lot of activity, maybe very little). All these options are in the help info or man pages, but in brief -d gives a CSV output, -z allows you to set the timezone, -m and -y set the date format, -b specifies a bodyfile, then comes the date range I'm interested in, and last -i specifies to generate an index; it's either "day" or "month", and must be redirected to the output file. Again, all I have to do is change "1" to "2", "jones" to "smith" and move on to the next.

Now my output directory has the following files:
001.fls, 001.l2t, 001.reg, body.001, index.001
This makes it easier for me to keep track of the different sets of data, and their formats. The pieces that go into my main bodyfile start numerically, and the combined datafiles end numerically. I know everyone has a different way; just wanted to share my logic/excuse.

I hope that can help someone. I should (hopefully) have some sort of shell script together tomorrow that would loop through the different hives for each custodian. There would still be several parameters to input initially, but it might work out to be faster going through four hives than up arrow, back arrow, replace... Once I have it I'll post that as well.


Note: Edited to correct mactime syntax to create index files.

No comments:

Post a Comment