Federal agencies are warning Gmail and Outlook email users of a costly ransomware scheme that has already affected more than 300 victims. The FBI and the U.S. Cybersecurity and Infrastructure Security Agency issued the advisory, detailing a warning about the Medusa hacking organization, which has been active since 2021.

The Federal Bureau of Investigation (FBI) has alerted Gmail, Outlook and VPN users over an impending Medusa virus attacks and its threat on infrastructure.

The FBI, MS-ISAC and CISA released a joint cybersecurity advisory about the Medusa ransomware variant, advising people and organizations to use multifactor authentication and other strategies to prevent attacks from the ransomware-as-a-service provider that has targeted hundreds since 2021.