One of the fun things I have been working on is the huge revision of the SANS Forensics 508: Advanced Forensics and Incident Response material. Rob Lee has spent the last ten years building and updating what has become one of the most well-known and respected digital forensics training courses. The golden age of hacking is in full swing and a whole host of new threats have emerged, including state-sponsored espionage (aka APT), hactivism, client-side attacks, and crimeware. Digital forensic investigations have never been more in demand. However, computer intrusion and malware investigations require a very different skill set than the cases seen by the average forensic examiner. Rob saw a great opportunity to update the FOR508 course to train this next generation of forensic professionals. I estimate that at least 60-70% of the course and nearly every exercise is new within the last year. My specific part in the course is writing the new memory forensics day. My forensic experience dates to the late 1990s, and I can’t remember any other advance in the field that has so fundamentally shifted the balance from the bad guys to the good guys. Memory forensics is now a mature discipline and we have a wonderful array of tools available, allowing us to analyze everything from raw memory files to hibernation files to crash dumps to live memory audits. Memory analysis is a game changing skill and we spend a significant part of the new 508 course learning and incorporating the results of that analysis into the broader forensic process.
Application Specific Geo-location
Web applications can often leave their own geo-location clues similar to those found via the mapping services. While mapping artifacts are largely consistent, geo-artifacts created by applications are more haphazard. Thus the number of available artifacts can be as numerous as the applications using geo-location services. To illustrate this, we will analyze the artifacts left by two popular location-aware applications: Flickr and Twitter.
Mobile Flickr Geo-artifacts
Understanding Browser Artifacts
Geo-location artifacts demonstrate an interesting concept with regard to browser-based evidence. Among the various browser artifacts, Internet history is a fan favorite because it provides such rich information. There is no easier place to look to identify sites visited by a specific user at a specific time. Browser history is so useful, a critical shortcoming is often ignored; with today’s dynamic web pages, the vast number of web page requests go unrecorded. When a user visits a website, a multitude of requests are completed in the background to retrieve images and advertisements, populate web analytics, and load content from third parties. The content retrieved from these requests is stored within the cache, and an entry within the cache database is created. While the browser history database may only show the page visited, the cache holds most of the components retrieved to dynamically build that page.
Geo-location artifacts have been a frequent focus of my research, and I am amazed at how quickly they are permeating operating systems, applications and file formats. In the fall of 2011 I had the pleasure of writing an article for Digital Forensics Magazine focused on browser-based geo artifacts, where much of this post was originally published.
One of the more revolutionary forensic artifacts to emerge in recent years is geo-location data. Geo-location gives us an accurate means to identify the physical location of an item on Earth. It is now possible to determine where in the world a laptop or mobile phone has been, solely using host-based forensics. In a world of increasingly mobile devices, geo-artifacts can provide a crucial extra dimension to our investigations. With it, we now have the potential to answer who, what, when, why, and where.
A year after release, the Malware Analyst’s Cookbook continues to elicit uniformly high praise from the security community. It is one of those rare books that only come around once every few years. The breadth of information covered is staggering, and it makes an excellent reference to return to as your skills develop. If I could make one recommendation, I would encourage readers to not wait to read the last four chapters of the book.
The last quarter of the book covers memory forensic analysis, and it is the definitive resource currently available on the subject (either online or in print). Continue Reading…