SANS Digital Forensics and Incident Response Blog: Tag - regular expressions

Data recovery with Hex Editor and RegEx

by Quinn Shamblin

In my previous postabout recovering mp3 data from a corrupted chip, I describe a data recovery challenge that I could not solve using FTK, Foremost or Lazarus. It turned out that Regular Expressionswere my answer. But how best to run regex-based data extractionagainst a forensic image when there might be hundreds of thousands, if not millions, of individual matching frames?

Hex Editor Neowas exactly what I needed. It has a few unique features that really

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Recovery of MP3s using regular expressions

by Quinn Shamblin

I was recently asked to recover audio MP3 from a corrupted memory chip.

The audio was recorded using a special-purpose audio recording machine configured to record in MP3 format in stereo 44.1KHz at 128kbps.

audio_editorThere are several tools and approaches that are sometimes helpful in automated data recovery. I tried Access Data's FTK, Foremost and Lazarus, but none of these worked in this case, so I needed a different approach.

An MP3 file is simply a sequential series of "frames", 417-418 bytes in length, that each have their own header that tells the MP3 player how to play that particular frame. If you carve out any single MP3 frame and save the result with a .mp3

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