Malware hackers using steganography in WAV audio files to hide malicious code

Beware the rogue .wav file.

Two reports published in the last few months indicate that authors of malware programs are using an interesting technique in their attacks.

Researchers report the bad guys are applying steganography techniques to hide malicious code inside .WAV audio files.

"The novelty in the two recently-published reports is the use of WAV audio files, not seen abused in malware operations until this year, Catalin Cimpanu at ZDNet reports:

The first of these two new malware campaigns abusing WAV files was reported back in June. Symantec security researchers said they spotted a Russian cyber-espionage group known as Waterbug (or Turla) using WAV files to hide and transfer malicious code from their server to already-infected victims.

The second malware campaign was spotted this month by BlackBerry Cylance. In a report published today and shared with ZDNet last week, Cylance said it saw something similar to what Symantec saw a few months before.

But while the Symantec report described a nation-state cyber-espionage operation, Cylance said they saw the WAV steganography technique being abused in a run-of-the-mill crypto-mining malware operation.

Cylance said this particular threat actor was hiding DLLs inside WAV audio files. Malware already-present on the infected host would download and read the WAV file, extract the DLL bit by bit, and then run it, installing a cryptocurrency miner application named XMRrig.

Josh Lemos, VP of Research and Intelligence at BlackBerry Cylance, told ZDNet in an email yesterday that this malware strain using WAV steganography was spotted on both Windows desktop and server instances.

WAV audio files are now being used to hide malicious code

[zdnet via]