How to detect if files were saved or copied to a USB drive?

Question

How can I find out if files from my computer were written/copied/moved to a USB storage device? I want to know if there is a solution that would work in a system that has not got any monitoring/logging of USB activity explicitly enabled and after the files have already been written.

I have already used software which would reads the information from registry location

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\USBSTOR

But it just tells the vendor name, time connected and other artifacts.

Answer 1

This will depend entirely on what logging you have enabled. It it's easy after the event to tell you to log all file copies etc, but if you weren't logging it, you won't be able to retrieve that info.

Answer 2

First, try to get the information about the devices that were plugged into the computer from the following locations

C:\Windows\inf\setupapi.dev

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Enum\USBSTOR 
HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Enum\USB

Be very particular when checking the Mounted devices key as this information will be required in future analysis

Analyse NTUSER.DAT file associated to that particular user in question. Go to NTUSER.DAT\Software\Microsoft\Windows\CurrentVersion\Explorer\MountPoints2 and search for the GUID of the device.

Module II:

If you use Encase or FTK search for key words (name of the file in question), analyse the .lnk files associated with the keyword. Parse the .lnk using FTK or Encase which will give you the path and the time stamp. If the path refers to a USB then try to match user's SID, USB serial number and the time stamp information.

You can even analyse MFT records and $Logfile which give you more information about the file structure.

Note: .lnk files will be created only the suspect opens the file in question from the USB drive.

Answer 3

I looked at a commercial offering called "Spector 360" that was talking about this exact scenario. As you might imagine, it required agents to be installed onto each monitored computer. Honestly, I was not happy with the system impact that the agents had on system performance. Enabling auditing/logging also has an impact on system performance. This is to be expected from pretty much any solution that is available to address the scenario you are describing.

Before I came across Spector 360, I knew of a Remote Administration Tool (RAT) that was being used to a small extent by criminals. The company that creates it is legit and was not necessarily responsible for the criminals actions; my point is that there are a lot of RAT/Spyware/Monitoring applications that will provide the functionality needed to accomplish what you desire. You should expect friction from AV installed on those systems though, no matter how legit the company that authored the application. They are all capable of being used malevolently.

As for forensically looking for evidence... maybe, but that is a long shot. I really wouldn't count on it. There would be artifacts created if the system conditions were right. Those artifacts would also be eroded according to the system conditions, usage, and time since the event.

Are you trying to determine if you have had some files stolen, or are you just wondering? If it is the latter, then you should really turn your attention towards the logging/auditing solutions. If you hand has been forced, you should just kill whom ever you suspect of stealing the files before they can distribute/deliver them. Burring their living space and surrounding areas to the ground would give a little more assurance that any stolen data was destroyed.

Of course, my last suggestion is illegeal and I am only kidding about actually carrying out such drastic measures. If you think you have had a security breach and want to talk it through with someone, you can contact me and I'll spend sometime helping you as much as I can.