The DoppelPaymer ransomware operation has made a rebranding move, now going by the name Grief (a.k.a. Pay or Grief) The gang has kept in the shadow to avoid the level of attention that REvil got for breaching Kaseya and DarkSide for hitting Colonial Pipeline, one of the largest fuel pipeline operators in the U.S. The gang also claims the recent attack on Greek city Thessaloniki, publishing a file archive as proof of the intrusion.
Source: https://www.bleepingcomputer.com/news/security/doppelpaymer-ransomware-gang-rebrands-as-the-grief-group/