[ProLock](https://attack.mitre.org/software/S0654) is a ransomware strain that has been used in Big Game Hunting (BGH) operations since at least 2020, often obtaining initial access with [QakBot](https://attack.mitre.org/software/S0650). [ProLock](https://attack.mitre.org/software/S0654) is the successor to PwndLocker ransomware which was found to contain a bug allowing decryption without ransom payment in 2019.(Citation: Group IB Ransomware September 2020)