Microsoft Corporation, a leading American multinational technology company reported on Friday that a Russian state-sponsored group, Midnight Blizzard hacked into its corporate systems and stole some emails and documents from its employees’ accounts.

The company said Midnight Blizzard also known as Nobelium is a Russian hacking group that used a “password spray attack” starting in November 2023 to breach a Microsoft platform. The hackers from the group used this technique to infiltrate into company’s systems, using the same platform across multiple sites.

Microsoft said that the group was able to access only a small percent of Microsoft corporate email accounts including members of its senior leadership team and employees involved in legal, cybersecurity, and other functions.

The threat research team at Microsoft regularly conducts investigations into nation-state hackers like Midnight Blizzard. According to the company, its examination of the recent breach revealed that the hackers initially focused on email accounts containing information about Midnight Blizzard.

“The attack was not the result of a vulnerability in Microsoft products or services. To date, there is no evidence that the threat actor had any access to customer environments, production systems, source code, or AI systems. We will notify customers if any action is required.” said Microsoft officials.

Upon receiving a request for comment, the Russian Embassy in Washington and the Ministry of Foreign Affairs did not provide an immediate response. Microsoft reported that it thoroughly investigated the incident and took measures to disrupt the malicious activity, effectively blocking the threat actor’s access to its systems.