Threat actors are abusing Microsoft Entra tenant invitations to run TOAD (Telephone-Oriented Attack Delivery) phishing campaigns that look like legitimate Microsoft 365 billing notifications. Instead of pushing links or attachments, they convince users to call attacker-controlled “support” numbers, where credentials and remote-access authorizations are harvested. This analysis explains how the attack chain works, which guest invitation properties are being misused, and how security teams can hunt for and mitigate these callbacks.