Posts tagged ‘tools’

Rookie

August 9, 2012
0

I recently embarked on my first solo analysis. To say I was nervous was an understatement, but I was determined to get it right. The case involved determining whether files on a rewritable DVD had been tampered with (edited or cut after first recorded) and the files in question were MPEG and text files. Tools used were Encase v6.18 and CD/DVD Inspector. I spent a number of rookie hours (like lethal forensicator hours but longer. 10 Rookie hours = 2 Lethal Forensicator hours) dissecting the DVD in both tools, bookmarking pertinent data, determining file creation, modified and last accessed dates, figuring out where the files in question started and ended on the disc and if there was any indication they had been edited. I also spent a great deal of time researching the file format (UDF) to make sure I had a good understanding of how and when the disc could be written to. This went on for a couple days at which time my boss asked for an update to give to the client. I rattled off my surely impressive analysis and research and, after some consideration, my boss’s only question was:

“Did you watch the video?”

PANIC!

“Uh…no… I was saving that for last…”

“Ok, sounds good so far. So watch the video and let me know, and then I’ll update the client.”

Wait?!?! Did he say I was doing good? YES!

[Insert fist pump moment]

And then I watched the video…

[Insert plane crash noise]

And discovered the content was not what I was expecting at all. The client had sent us the wrong DVD.

What did I learn:

1) Validate your evidence to ensure you have what you think you have… especially when you weren’t responsible for the collection.
2) Plan your analysis before you start. Figure out what steps have the greatest value and how they will lead into other steps.
3) Keep it simple, Stupid! In my case, nervousness over wanting to do well made me overlook the obvious.

Epilogue:

This week I received another DVD from the client and the first thing I did was verify the files on the disc by watching the videos. Despite my slight embarrassment from my first run at this case, it was actually a great way to get all my anxiety out of the way. This time I was able to focus more on the case and the tools, and less on wondering if I was doing a good job. In the end, I was able to gather enough evidence to give the client an answer my boss and I were both confident with.

Always wear cargo pants…

July 17, 2012
1

This is practical advice for a lot of situations, but particularly when I found myself at the SANS DFIR Summit and Forensics 508 this past June in a facilitator role. Never having volunteered for SANS before, I carefully packed my best tan and black dress pants and headed off to Austin. Once there, I realized quickly the need to be carrying around my own personal junk (wallet, cellphone, room key, SHINY NEW LETHAL FORENSICATOR COIN!!!) as well as all the stuff required for my day with SANS – pen, sharpie, yellow cards, etc) but for the most part had no pockets to carry it in. There were also a few times when I wished I had something like a small pocket knife for opening boxes but had to run and search for some scissors instead.

Now, to get all existential on you, I learned about a number of great forensic tools, some of which have similar functions (Mandiant Redline and Volatility) and some of which are unique (log2timeline).  As well, I learned to appreciate some of the basic skills that should be acquired prior to using these tools. I have only just begun my journey as a forensicator but it occurs to me that we should be prepared to handle an incident at a moment’s notice. That means we should be ready and wearing our metaphorical cargo pants packed with as many useful tools and skills as we can carry. Each incident is unique but having pre-packed “pockets” can help us react more nimbly and effectively.  For example, while having two tools that basically do the same thing may seem redundant, the skill part of the equation lies in knowing the tools well enough to understand that each tool may give you slightly different, but complimentary results to assist you in finding your answers. Some tools might seem intuitive to include but just like a pocket knife, may come in handy in ways you don’t expect. What if the MBR is corrupt on the drive you are working on and your usual go-to tools can’t see any partitions? Do you know enough about the basics of file partitions and where to start looking for them on a drive image using a common hex editor?  I do now, thanks to Rob Lee and SANS FOR508.

The point I’m trying to make (and I assure you I do have one) is that just like being a Scout, being prepared is the lesson I took home from SANS DFIR Summit 2012.  I am planning to practice new skills, find new tools and learn from and contribute to my new-found DFIR family until next year…when I will definitely be wearing cargo pants.