The FBI and the U.S. Cybersecurity and Infrastructure Security Agency are urging users of popular email services like Gmail and Outlook to be on the lookout for a dangerous and potentially costly ransomware scheme. A bulletin released this week detailed a warning for the Medusa ransomware gang, a group that’s been active since 2021.

The FBI has issued a warning about ransomware threats targeting the United States Postal Service and Gmail and Outlook users. According to the agency, the Medusa ransomware gang—an organization that has been active since 2022—is behind the attacks.

The FBI has sounded the alarm for Gmail and Microsoft Outlook users about a malicious program known as Medusa, which has hijacked the data of hundreds of victims.This ransomware has ensnared over 300 individuals across "critical infrastructure sectors,