An elite hacking group sponsored by Russian intelligence gained access to the emails of some of Microsoft's top executives starting in late November, the company revealed in a blog post and regulatory filing on Friday.
Microsoft said it had discovered the intrusion a week ago and was still investigating. The hackers appeared to focus on reviewing Microsoft corporate email accounts for information related to the hacking group, which Microsoft researchers called Midnight Blizzard.
The hackers reviewed emails from Microsoft's senior leadership team, as well as cybersecurity employees, legal groups and others, and took some emails and attachments, the company said. The company, which had worked with cybersecurity companies and governments to investigate previous attacks by the hacking group, did not name the executives whose emails were attacked.
Russia's Foreign Intelligence Service has run the hacking group since at least 2008. according to the US Cybersecurity and Infrastructure Security Agency. The group is known by a variety of nicknames, including Cozy Bear, Dukes and APT 29, and has been behind a number of high-profile attacks, according to previous investigations by the U.S. government.
Targets include the Democratic National Committee's computers in 2015 and technology provider SolarWinds, which allowed Russia to gain access to systems at the State Department, the Department of Homeland Security and parts of the Pentagon in 2020. called That incident was “the most sophisticated cyberattack on a nation-state in history.”
The method used in the new hack appears to be less exotic: a relatively basic tactic known as password spraying, in which hackers test common passwords across a wide range of accounts. The group, which it has been known To use this tactic, he found an opening in an old account for a test system and then used that account's permissions to gain access to corporate email accounts, Microsoft said.
“To date, there is no evidence that the threat actor had access to customer environments, production systems, source code, or artificial intelligence systems,” Microsoft said in a statement.
The regulatory filing said the company had notified and was working with authorities.
Microsoft, which supplies technology to many Western governments, has long been a target of nation-state hacking. Last year, Chinese hackers breached Microsoft systems and gained access to the email accounts of Commerce Secretary Gina M. Raimondo and other government officials.
