https://www.bleepingcomputer.com/news/security/revil-ransomware-returns-new-malware-sample-confirms-gang-is-back/

The notorious REvil ransomware operation has returned amidst rising tensions between Russia and the USA, with new infrastructure and a modified encryptor allowing for more targeted attacks.

In October, the REvil ransomware gang shut down after a law enforcement operation hijacked their Tor servers, followed by arrests of members by Russian law enforcement.