Microsoft Alerts: Phishing Uses Email Routing and DMARC Gaps
📧 Microsoft’s Threat Intelligence team warns that attackers are increasingly exploiting complex email routing and misconfigured DMARC and SPF policies to make phishing messages appear to come from inside targeted organizations. These campaigns often rely on MX records that route mail through on‑premises servers or third‑party relays before Microsoft 365, which can prevent correct spoof checks. Threat actors deliver lures ranging from password resets to shared documents and use PhaaS platforms such as Tycoon 2FA. Microsoft advises enforcing strict DMARC reject and SPF hard-fail policies, verifying connectors, and adopting phishing-resistant MFA like FIDO2 keys.
