Cyber Criminals Exploit Email Rule Vulnerability

Summary

The COVID-19 pandemic prompted a mass shift to telework among many US businesses, resulting in increased use of web-based email applications. According to recent FBI reporting, cyber criminals are implementing auto-forwarding rules on victims’ web-based email clients to conceal their activities. The web-based client’s forwarding rules often do not sync with the desktop client, limiting the rules’ visibility to cybersecurity administrators. Cyber criminals then capitalize on this reduced visibility to increase the likelihood of a successful business email compromise (BEC). BEC schemes resulted in more than $1.7 billion in worldwide losses reported to the Internet Crime Complaint Center (IC3) in 2019. The FBI is sharing this information to inform companies of this email rule forwarding vulnerability, which may leave businesses more susceptible to BEC.

This FBI PIN contains an overview of the threat, recommended mitigations, and is being provided to assist cybersecurity professionals guard against the persistent malicious actions of cyber actors.

Reporting

We encourage recipients who discover signs of malicious cyber activity to contact us via the cyber incident report form by clicking here.