De-Anonymizing Live CDs through Physical Memory Analysis presented at BlackHatDC 2011

by Andrew Case,


Summary : Traditional digital forensics encompasses the examination of data from an offline or dead source such as a disk image. Since the filesystem is intact on these images, a number of forensics techniques are available for analysis such as file and metadata examination, timelining, deleted file recovery, indexing, and searching. Live CDs present a large problem for this forensics model though as they run solely in RAM and do not interact with the local disk. This removes the ability to perform an orderly examination since the filesystem is no longer readily available and putting random pages of data into context can be very difficult for in-depth investigations. In order to solve this problem, we present a number of techniques that allow for complete recovery of a live CDs in-memory filesystem and partial recovery of its previously deleted contents. We also present memory analysis of the popular Tor application as it is used by a number of live CDs in an attempt to keep network communications encrypted and anonymous.