Microsoft's Azure MFA Phonefactor is a multi-factor authentication solution that secures access to resources like VPNs, remote access logins, and IIS-hosted web applications. It challenges users for a second factor of authentication through several methods, including automated phone calls which can optionally require a PIN, one-way or two-way SMS messages, and push notifications to a companion mobile app. The system includes a user self-service portal for enrollment and management of verification preferences, provides fraud alert and blocking capabilities, and logs all authentication events for administrative reporting and monitoring.
