Avast releases free AtomSilo and LockFile ransomware decryptor based on weakness in AtomSilo ransomware

On Wednesday 27th of October 2021, Avast, a Czech cybersecurity software firm announced that they had released a free decryption tool for AtomSilo and LockFile ransomware victims based on a weakness in the AtomSilo ransomware that found by RE – CERT malware analyst Jiří Vinopal. The decryptor is valid for both kinds of ransomware strains as they are very similar even though the attack tactics used by the different threat actors are different.

Avast has warned that a decryptor may not be able to decrypt files with unknown, proprietary, or with no format at all as it “relies on a known file format to verify that the file was successfully decrypted. For that reason, some files may not be decrypted,”

The decryption tool is available for download from Avast’s servers and can decrypt entire disk partitions using the instructions displayed within the decryptor’s UI.