It's been a busy time in digital forensics and incident response (DFIR). Every summer, for over 20 years, infosec and forensicators and old school hackers have gathered in Las Vegas. A mixture of very deep tech talks, trainings, and technology oriented distractions "flood the zone" in Las Vegas. Close to 15-20,000 people were in Las Vegas this summer for what has now evolved into three separate conferences, all in the same week.
July 27th was the start of Black Hat atCaesars Palace in Las Vegas. The conference kicks off with training in the last weekend of the month, and finishes onWednesday, July 31st and Thursday, August 1st, with lectures and technical demonstrations, called "Black Hat Briefings." This year, in the wake of the NSA/Snowden rowe, NSA Director, General Keith Alexander gave the opening keynote. Black Hat was more corporate than ever, with more sponsor banners, and sponsor-generated talks (disclosed by the organizers, and placed in a separate area, bravo!)
SANS expanded the Reverse-Engineering Malware course (FOR610) to include a day's worth of capture-the flag malware analysis challenges. The challenges are built upon the NetWars tournament platform and are designed to reinforce the skills learned earlier in the course by experimenting with real-world malware. You can get a sneak peak at the new experience.
A key component of any investigation is the type of data exfiltrated. If sensitive data is on a compromised machine, risk is increased significantly. Also, there is a patch work of legislation covering various types of data which is considered sensitive (http://www.reyrey.com/regulations/). In general, social security and credit card numbers are at the top of the concern list. Since many states have encryption exemptions, a forensicator needs to know, does any media storage in the case have sensitive data in the clear?
Data can be encrypted by system administrators/DBAs or by attackers. Attackers usually encrypt data as part of the staging process prior to data exfiltation. Attackers commonly password protected and compressed the data as a .rar file. With strong passwords (32+ character pass-phrases) .rar files can be difficult to almost impossible to open with normal computing power.
Using a cross
There are numerous ways of concealing sensitive data and code within malicious files and programs. Fortunately, attackers use one particular XOR-based technique very frequently, because offers sufficient protection and is simple to implement. Here's a look at several tools for deobfuscating XOR-encoded data during static malware analysis.
MASTIFF is an open source framework for automating static malware analysis. This tool, created by Tyler Hudak, determines the type of file that is being analyzed and then applies only the static analysis techniques that are appropriate for that file type. MASTIFF offers a useful way for performing triage on a large set of suspicious files.