Forensic Analysis of Virtual Hard Drives

The issue of the volatility of virtual machines is perhaps the most pressing concern in any digital investigation involving a virtual machine. Current digital forensics tools do not fully address the complexities of data recovery that are posed by virtual hard drives. It is necessary, for this reason, to explore ways to capture evidence, other than those using current digital forensic methods. Data recovery should be done in the most efficient and secure manner, as quickly, and in an as non-intrusive way as can be achieved. All data in a virtual machine is disposed of when that virtual machine is destroyed, it may not therefore be possible to extract and preserve evidence such as incriminating images prior to destruction. Recovering that evidence, or finding some way of associating that evidence with the virtual machine before destruction of that virtual machine, is therefore crucial.In this paper we present a method for extracting evidence from a virtual hard disk drive in a quick, secure and verifiable manner, with a minimum impact on the drive thus preserving its integrity for further analysis.