Teams Messaging Policy Changed to Allow External B2B Invites

Mehulkumar Savajani@Msavajani

•updated Nov 28, 2025•22•1•207

Detects when a Microsoft Teams messaging policy is modified to allow users to send B2B invitations to external users ('UseB2BInvitesToAddExternalUsers' set to 'True'). While this can be a legitimate administrative change, it can also be an indicator of misconfiguration or malicious activity to enable phishing attacks by luring users to malicious external tenants where organizational security controls do not apply.