A new step in the evolution of ransomware has been documented by security researchers who have discovered a sample of malware that encrypts files in the storage drive and creates unique strands of itself because of its polymorphic features.
The new threat has been named VirRansom and VirLock by researchers from Sophos and ESET, respectively. This crypto-malware, unlike any of its kind, allows the files to be decrypted, but this will not stop blocking the victim's computer screen. In this way he causes the victim to pay.
Just the Ransomware Run on the victim's computer is embedded in a portable executable Portable Executable (PE) and adds the EXE extension.
It is noteworthy that malware scrambles the files it affects, but also decrypts it when it is executed.
Once the user runs the infected file, the virus automatically starts spreading to the system. ESET researchers report that in two cases it landed on "% userprofile%" and "% AllUsersProfile%".
According to the researchers' analysis, VirLock can infect documents (DOC, XLS, PDF, PPT), images (PNG, GIF, BMP, PSD, JPG), audio files (MP3), MPG compressed files (RAR, ZIP).
It looks like at the moment there are at least six variants of the malware running on the Internet.
If VirLock / Ransom malware does not encrypt victim files as the other crypto-malware does, it locks the computer screen to achieve its target.
When the computer is in a locked state, malware shuts down explorer.exe, prevents opening of Task Manager, and other procedures that could help to bypass it, according to ESET.
The message about the ransom threatens classically with legal consequences, for some alleged copyright violations, and asks for 216 in bitcoins.