Enlarge image
Microsoft logo on a building
Photo: Rolf Vennenbernd/dpa
Uninvited guests: Microsoft cannot get Russian hackers, who recently gained access to some of the company's high-ranking managers' emails, out of its systems.
In recent weeks, the attackers have accessed, among other things, collections of software source code, Microsoft announced on Friday.
It cannot be ruled out that hackers will continue to gain unauthorized access in the future.
The attackers also tried to use secrets found in the stolen emails from communication between the company and its customers for their own purposes, it was said without further details.
Microsoft warns those affected.
Microsoft said in January that hackers with ties to the Russian government had been able to read some emails from senior managers, cybersecurity and legal staff since November.
The hackers also downloaded some documents from email attachments.
At the time, it was said that there was no evidence that the attackers had gained access to software source code.
The group has not yet provided any information about who among the group's management is affected.
According to Microsoft, the hackers got into the email system after cracking the password of an internal test account.
According to Microsoft, a Russian group known as “Midnight Blizzard” and “Nobelium” is behind the hack.
The attackers poured a lot of resources into the ongoing attack, Microsoft wrote in a blog post.
In a statement to the Securities and Exchange Commission (SEC), it was also stated that the company did not assume that the attack would have significant consequences for its financial situation.
Microsoft has increased investments in security and is working with investigative authorities.
dop/dpa