Monday, August 26, 2013

Daily Blog #64: Sunday Funday 8/25/13 Winner(s)!

Hello Reader,
           Another Sunday Funday has come and gone and this week I decided to change things up again. I gave out two questions and allowed people to either answer one or both of them. I thought this would be a fun way to allow for varying levels of difficulty within the same challenge. I had several good responses and picking a winner was tough.

The Challenge:
Two questions this week! Answer one or both for those over achievers:
Question 1:
Your client has a home computer running Windows 7 and uses Internet Explorer for his web access. He has switched jobs and is working on a competing product. An opposing expert has issued a report stating that your client must have accessed a website containing the new competing product earlier than the internet history shows because he found the same fragment of a page found in the unallocated space of a shadow copy he imaged. He is alleging that this earlier access shows he was working for the competitor before he quit his job.

Why is he wrong?

The Wining Answer:
Sajeev Nair
Unallocated is not monitored by VSS, so what they were seeing was the general unallocated and not associated with VSS. Only volumes are tracked. 

This can be confirmed by 
checking the registry value HKLM\SOFTWARE\Microsoft\WINDOWS NT\CURRENTVERSION\SPP\Clients\ {09F7EDC5-294E-4180-AF6A-FB0E6A0E9513}, this value determines which volume is currently monitored by VSS. 

Additionally, the below registry key determines, which files are not copied  by VSS. 

HKLM\System\CurrentControlSet\Control\Backup Restore\FilesNotToSnapshot
What I liked about this answer is that they included the registry keys to see what is and is not being included within VSS snapshots. The second place answer actually talked about overlays which was great, but looked at it from a live system perspective rather than the issue at hand. There is more to this and Joachim Metz's papers are great place to start if you want to understand the possible misinterpretations you'll likely have to face in the future.

Question 2:
Your suspect  has a new work computer running Windows 7 and uses Google Chrome to access the internet. He has switched companies and used to work for your client. You have found Google Chrome history that predates his employment at the new company that reflects accesses to your clients system. 

Why is the activity there?

The Winning Answer:
Paul Bobby

You can 'log in' to Google Chrome, so to speak. Browsing history from other devices, such as home computers or previous work computers, that also use Chrome (and log in to synch changes) are now visible on this new work computer.
If you synch Chrome by 'signing in', open a new tab. In the lower right you will see an "other devices" pull down.

What I liked about this answer is mentioned not just about the Chrome sync service but also how to identify where the other devices are. Knowing how to distinguish what system is creating the history Chrome shows is important when assigning activity to a system!

Thanks everyone for playing! Winners please send me a message for what prize you are picking. Tomorrow its back to either the business of forensics or finishing the understanding the artifacts series.