https://www.bleepingcomputer.com/news/security/clop-ransomware-claims-responsibility-for-moveit-extortion-attacks/

The Clop ransomware gang has told BleepingComputer they are behind the MOVEit Transfer data-theft attacks, where a zero-day vulnerability was exploited to breach multiple companies' servers and steal data.

This confirms Microsoft's Sunday night attribution to the hacking group they track as 'Lace Tempast,' also known as TA505 and FIN11.