Offenders gained access to 3% of e-mail boxes in this service based on Microsoft software.
The Justice Department received information about unknown malicious activity related to SolarWinds and affecting federal agencies and technical contractors.
''As part of the ongoing technical analysis, the Department has determined that the activity constitutes a major incident under the Federal Information Security Modernization Act, and is taking the steps consistent with that determination. The Department will continue to notify the appropriate federal agencies, Congress, and the public as warranted," said in the message.
Earlier, the American company - the developer of the anti-coronavirus vaccine Moderna Inc. suffered from hacker attacks. The company received information about the unauthorized access of cybercriminals to its data from the European Medicines Agency (EMA). This structure had at its disposal documents related to preliminary negotiations on a drug candidate for a Covid-19 vaccine developed by Moderna Inc. It was this information that was of interest to the attackers and, subsequently, they received it.