Monday, March 23, 2009

Using Volatility for Introspection

This post could also be titled "Teaser", part 2 :)

As part of my research at GT, I've been looking at using Volatility to examine the state of running virtual machines. Using PyXa, a wrapper around Bryan Payne's XenAccess library (available in the tools directory of the latest XenAccess release), you can get access to the memory of Xen guest VMs in Python. From there, it's just a small step to create a new address space that Volatility can use to examine virtual machines just as if they were any other memory image.

One application of this is using introspection to find out the state of windows on screen. This has advanced significantly since the last time I mentioned it, and it's now possible to track windows, including their z-order and some on-screen text, in near-real time. To demo this I used Volatility to examine the internal data structures of Win32k.sys and extract the locations and sizes of all visible windows, and then used PyGame to draw them on screen. The script keeps looping and re-drawing, allowing a near real-time view of what's going on inside the guest VM.

Here's a video of it in action. Notice how the reconstructed view updates to match what's actually going on on screen:



Cool, huh? :D

7 comments:

JL said...

Awesome work! I was wondering what the teaser was earlier :-)

Danny said...

Very cool!

Sippy said...

Brendan,

Nicely done. No - that's just SEXY!

Sip

Golden G. Richard III said...

This is very cool. I don't suppose you have any ideas for a similar analysis of VMWare virtual machines?

moyix said...

I think doing this should be possible with VMWare's VMSafe API, though I haven't gotten to play with it yet to be sure. All you need is some way of accessing physical memory, which means it's pretty generally applicable.

You could also do this with an interface to Qemu, a physical RAM capture card (like some folks at Rutgers are doing), or anything else that gets continuous access to physical memory :)

Yeongjin Jang said...

I just re-watched this things and this is super AWESOME!
Using Volatility (a forensic tool) to VMI is cool idea, and you are giving a practical proof that how far we can get from the combination. Kudos to you, ;)

Brendan Dolan-Gavitt said...

Thanks Yeongjin! :) Bryan and I actually had a paper many years ago about other ways to use Volatility for VMI: https://smartech.gatech.edu/handle/1853/38424