SANS Digital Forensics and Incident Response Blog: Category - Evidence Analysis

Digital Forensics Case Leads: New Gear, New PDFs Abuse, and Defeating TrueCrypt

Logicube releases new forensics gear, Didier Stevens discovers a new way to do interesting things with a PDF and a cooperative user, and Passware provides a means to defeat TrueCrypt.

Logicube has released two devices which look interesting. The MPFS or Massive Portable Forensic Storage provides up to 8TB of storage capacity for acquiring multiple images. The device may be attached to a forensic analyst's workstation via firewire, USB, or eSATA. The unit is compatible with Logicube's Dossier imager and Logicube's second new device, the NETConnect which as the name suggests, allows network access to forensic images. Based on the description, NETConnect is essentially a file server which enables multiple investigators to access forensic images as soon as they are acquired. The device supports Windows, Mac, and Linux and includes support for CIFS and NFS. (I've not had the opportunity to test either device but if Logicube or anyone else wants to send me a set, I will be

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Digital Forensic Sampling

Robert-Jan Mora and Bas Kloet have released an interesting paper called DigitalForensicSampling.pdf and it's about applying statistical sampling to digital forensics. Digital forensic practitioners are frequently faced with extremely large amounts of data to analyze, a situation that looks to get worse as storage capacities continue to increase. Mora and Kloet propose the use of random sampling for certain types of cases as a means of alleviating this problem.

Here's a quote from the paper's introduction:

In this paper we would like to address a few problems that we encounter in the digital forensic field,in general, which probably will get worse if our methods do not get smarter soon. A few problemsthat the digital forensic community has to deal with are:

  • The amount of data that needs to be investigated in cases increases every year;

Nokia n900 mobile forensic cheat sheet

Nokia N900
Shadowed by coverage of all things Nexus and iPad, Nokia's new n900 is the unsung hero of the smart phone world. That's just fine for folks like DT and HD and anyone else looking for a *phone* that runs nmap, aircrack, metasploit and wireshark. Future functionality includes backtrack itself packaged as neopwn v2!

Cutting to the chase then this is a quickie cheat sheet about forensic artifacts on the n900 and where to find

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RSA 2010 - Digital Forensic Analyst Notebook

The RSA Security Conference was held this week in San Francisco. The conference is jammed packed with sessions, whiteboarding events, demonstrations, and more. Here are my observations and interview sound bites. I was covering RSA San Francisco 2010 as a forensic analyst and co-host of The CyberJungle, a weekly live news and talk program on security, privacy, and the law.

Digital forensics is still the non-sexy topic at RSA Security. There were no dedicated forensics tracks for this conference. But computer forensics were mentioned now and then in session talks, although many times by the audience more than the speakers.

Smart Grid Forensics
For example, there was an industry panel on electric smart grid security standards. The panelists in this session did not have forensics on their agenda, but a member of the audience did. Gerry Brown is an independent forensics consultant.

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Extracting Known Bad Hash Set From NSRL

Hash filtering is a time-saving technique for a computer forensics examiner when working on a huge disk image. In a nutshell, this technique can filter out all those files in your image that belong to the operating system or well-known software packages. This will let the examiner focus on unknown files, reducing the scope of the investigation. After all, there's no point in spending time checking files we already know.

This filtering operation is based on hashes. Usually, we calculate the hash for every file in the image and check it against a list of hashes previously calculated over known good files. We call this list the known good hash set. All files with hashes matching the list are filtered out.

On the other hand, we would like to know if there are malicious files in our computer forensics case image. Again, the technique works by calculating the hash for every file in the image, looking for matches in a list containing pre-calculated hashes for known malicious

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