Getting fuzzy
In the constant arms race of malware authoring and Digital Forensics and Incident Response (DFIR) analysts attempting to find solutions to common obfuscation techniques, hashbusting has also been addressed in the form of fuzzy hashing.
ssdeep
is a fuzzy hashing algorithm that utilizes a similarity digest in order to create and output representations of files in the following format:
chunksize:chunk:double_chunk
While it is not necessary to understand the technical aspects of ssdeep
for most analysts, a few key points should be understood that differentiate ssdeep
and fuzzy hashing from standard cryptographic hashing methods such as MD5 and SHA256: changing small portions of a file will not significantly change the ssdeep
hash of the file, whereas changing one bit will entirely change the cryptographic hash.
With this in mind, let's take a ssdeep
hash of our 8888888.png
sample. Unfortunately, ssdeep
is not installed by default in FLARE VM, so we will require...