Russian state-sponsored hackers, named Midnight Blizzard, breached Microsoft's corporate email accounts, compromising communications with U.S. federal agencies.

The Cybersecurity and Infrastructure Security Agency (CISA) has issued an emergency directive to handle the breach and secure the affected credentials.

The hackers, associated with Russian intelligence, escalated their attack efforts in February and gained access to Microsoft's source code and internal systems.

Microsoft is actively notifying customers whose confidential information was exposed in the stolen emails to help them take protective actions.

The initial breach method was a password spray attack on a test account lacking multifactor authentication.

The same hacking group also infiltrated Hewlett Packard Enterprise's cloud-based email service.

Senator Ron Wyden criticized Microsoft's cybersecurity measures and called for accountability in the wake of the breaches.

The threat from the Midnight Blizzard group remains ongoing, with continued efforts to address and mitigate the consequences of their cyber intrusions.