Blackberry File Detetion and Thumbnail Caches

BlackBerry devices are not typically welcome arrivals within a forensic lab; their robust security often making examination difficult. In this article we will look at some interesting aspects of the FAT implementation used in BlackBerry devices, and how thumbnail caches can provide a valuable source of evidence.

In situations where access to data within a BlackBerry handset itself is not immediately available (for example, due to an active device password), the recovery of live and deleted data from the memory card becomes even more important. There is nothing too surprising about how Research In Motion (or RIM as the BlackBerry manufacturer is more commonly referred to) has provided removable storage within modern BlackBerry handsets. A microSD card is used, formatted using Microsoft’s FAT fi le system; a solution which is ubiquitous within the industry due to the widespread compatibility of FAT. Naturally the first step is to create (and hash) a forensic image of the card such that analysis and evidence recovery can take place.