Microsoft announced on Friday that the Russian state-sponsored hacker group Midnight Blizzard was attempting to breach its networks using data that it had taken from the tech giant's business emails in January.
The goal was to get new access to the tech giants servers, whose products are frequently used by the US national security establishment, according to Reuters.
Some experts showed concerns over the disclosure, citing worries about the security of Microsoft's systems and services. Microsoft is one of the biggest software companies in the world and supplies the US government with digital services and infrastructure.
The hacker collective known as Nobelium gained access to Microsoft's corporate email networks in January and took emails and documents from staff accounts.
“In recent weeks, we have seen evidence that Midnight Blizzard is using information initially exfiltrated from our corporate email systems to gain, or attempt to gain unauthorized access,” the company said in a statement on its blog.
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According to US tech giant, this data covers a portion of its internal systems and source code repositories.
After hearing the news, the company's shares slightly declined.
“It is apparent that Midnight Blizzard is attempting to use secrets of different types it has found,” the company added. “Some of these secrets were shared between customers and Microsoft in email, and as we discover them in our exfiltrated email, we have been and are reaching out to these customers to assist them in taking mitigating measures.”
The corporation claimed that the hackers had grown somewhat more active in their attempts to break into Microsoft.
For example, compared to their January attack, Microsoft reported that the hackers' usage of "password sprays," in which an attacker uses the same password on many accounts in the hopes of getting in, had grown by up to 10 times.
Requests for a response about Microsoft's claims regarding the Midnight Blizzard attack have previously gone unanswered by the Russian embassy in Washington.
The tech giant stated that there is no proof that the attack has affected any of its customer-facing systems.
