Microsoft said it thwarted Chinese hackers who targeted customer email accounts at government agencies throughout Europe and the United States in a cyberattack.
In a statement Tuesday, Microsoft said the attacks targeted about 25 agencies, including government agencies, as well as individuals associated with them through apparent cracks in Microsoft’s security systems.
“Microsoft has completed mitigation of this attack for all customers,” the company said in a statement, adding that “no customer action is required.”
Microsoft placed blame on Storm-0558, which it described as “an adversary based in China” who was “focused on espionage.”
Microsoft said its engineers detected the breach on June 16, but a preliminary investigation has since determined the trail of anomalous mail activity went back as far as May 15, when a Chinese-based hacker identified as Storm-0558 first gained access to Outlook email accounts.