FBI TLP White PIN: FBI Disrupts Cyber Actors’ Exploitation of Microsoft Exchange Server Vulnerabilities April 13, 2021

On 13 April 2021, the Federal Bureau of Investigation (FBI) conducted a court-authorized operation to remove hundreds of malicious web shells from vulnerable servers in the United States in response to the widespread exploitation of critical Microsoft Exchange Server (MES) vulnerabilities by malicious cyber actors. The servers ran on-premises versions of MES, a software used to provide enterprise-level e-mail service. This is unrelated to Microsoft’s 13 April announcement of security updates for additional MES vulnerabilities. View the entire report below.