Ghost-Sender Internal Spoofing Attempt
Identifies inbound emails claiming to be from an internal domain where the sender IP does not match the expected authorized third-party MX record or spam filter IP addresses. This rule focuses on emails successfully delivered to the user, where the sender domain claims to be one of the organization's internal domains, and the sending IP is not among the expected external MX or spam filter IP addresses.
Microsoft Sentinel (KQL)
