Phishing Actors Exploit Complex Mail Routing and Spoofing
📧 Phishing actors are exploiting complex mail routing and misconfigured spoof protections to send messages that appear to originate internally, frequently using PhaaS platforms such as Tycoon2FA. Microsoft observed increased use of this vector since May 2025, including nested redirect chains and AiTM techniques to harvest credentials. Tenants with MX records pointed to Office 365 benefit from built-in protections; others must enforce strict SPF hard-fail, DKIM signing, and DMARC reject policies and correctly configure connectors to prevent these spoofing campaigns.
