Microsoft Warns Misconfigured Email Routing Can Enable Internal Domain Phishing

Threat actors engaging in phishing attacks are exploiting routing scenarios and misconfigured spoof protections to impersonate organizations' domains and distribute emails that appear as if they have been sent internally. "Threat actors have leveraged this vector to deliver a wide variety of phishing messages related to various phishing-as-a-service (PhaaS) platforms such as Tycoon 2FA," the

source https://thehackernews.com/2026/01/microsoft-warns-misconfigured-email.html