From Fortune:

State-backed Russian hackers were able to breach Microsoft’s corporate email system, gaining access to leadership accounts, cybersecurity and legal teams. Just a small percentage of accounts were accessed, but some emails and attached documents were stolen. The attack began in November, discovered in January. Microsoft has not yet determined the financial impact. Hacking usually focuses on government entities.

Microsoft calls the hacking unit Midnight Blizzard. Prior to revamping its name last year, it called itself Nobelium. The cybersecurity firm Mandiant, owned by Google, calls the group Cozy Bear. They were also responsible for last year’s SolarWinds hack which affected dozens of government agencies and private companies. The SVR primarily targets U.S. and European governments, diplomats, and think tanks.



Read more: Russian hackers broke into Microsoft’s corporate email system and gained access to some accounts of the company’s leadership team