UK's Home Office had its corporate emails compromised by Russian state-backed threat operation Midnight Blizzard, also known as APT29 and Cozy Bear, following the hack of the government agency's corporate service provider Microsoft, reports The Record, a news site by cybersecurity firm Recorded Future.
Such a breach, which was only reported by the Home Office to the country's Information Commissioner's Office four months after being disclosed by Microsoft, was noted by a Home Office spokesperson to not have impacted the agency's systems.
The development is part of escalating Russian cyberattacks against the UK since it began its invasion of Ukraine in February 2022, said Orbis Business Intelligence Director Christopher Steele. U.S. federal agencies were previously noted to have been affected by the Midnight Blizzard attack against Microsoft, with the Cybersecurity and Infrastructure Security Agency disclosing Microsoft's promise to provide metadata for all the stolen federal agency messages in aid of an ongoing investigation into the incident.