Sometimes as an incident responder we get called on to analyze a system that has already been “looked at” by another admin or desktop support personnel. Most of the time, I tell them the evidence has been trampled on by different malware scanning software and just re-image the system. But, sometime you may need to do analysis on the system.
In this instance, a number of different malware products had been ran, along with clearing temp files and Internet cache, but the system was still showing signs of infection. After building a timeline , I was able to determine that the initial infection vector had been deleted and the malware hosting site had been pulled off-line. The system had a nasty rootkit that was injecting code into a couple of processes. I didn’t have time to run it through ollydbg or Ida Pro.
I needed a quick way of determine the capabilities of the malware, so I decided to boot a copy of the original dd image using vmware and then do behavioral analysis on the system. I could have used software such as Live View, but I wasn’t sure how well it worked with Linux as my host OS. Harlan Carvey did a great post in 2007 about booting a dd image using vmware, I wanted to turn that idea into a procedure.
- Make sure you are using a backup copy of the dd image, as this will make changes to the image file.
- Launch Prodiscover Basic
a. Select ->Image convert tools -> Vmware support for DD Images
- Select the dd file
- In the same folder as the dd file it will create a .vmdk file.
5.Create a new virtual machine. Use the wizard and select typical machine, install OS later and Guest OS and take default setting on all the rest.
6.Select VM Settings. Under VMware 7.0 choose the Vm Menu ->Setting
7.Remove the default hard drive
8. Select add-> hard disk then next
9.Select use existing virtual disk. Browse to the new vmdk file created.
10. Boot the VM.
11. Use the process described in a previous post to determine what the malware is doing. Make sure that you use the applications that you are worried about the malware interacting with. For example, if you are worried about a web-based credential stealing malware, try logging into site like E-bay, Citibank and maybe a custom app from your company. Make sure you are using fake credentials if you do not want to potentially leak real ones.
Dark reading just recently had a post on a Java based command line tool to for doing this. I have yet to use it, but it may be worth checking out.