Microsoft has warned customers a hacker may have gained access to personal details through one of its service agents and then used information to launch hacking attempts against them.
The company found the compromise during its response to hacks by a team it identifies as responsible for earlier major breaches at SolarWinds and Microsoft.
Microsoft has warned the affected customers and said the attacker belonged to the group called Nobelium.
The SaaS giant said the nation-state hacker gained access to the information during the second half of May.
The US government has publicly attributed the earlier attacks to the Russian government which denies involvement.
