
Microsoft has announced that its new brand impersonation protection feature for Teams Chat will be fully deployed to all customers by mid-February 2025. This security enhancement aims to combat phishing attacks targeting organizations using external Teams access.
Key Features and Implementation:
– Automatic alerts when detecting potential impersonation attempts
– No administrative configuration required
– Default enabled status upon release
– High-risk warning system in Accept/Block flow
– Mandatory message preview before user action
The security measure comes in response to various cyber threats, including attacks from state-sponsored actors like Midnight Blizzard, who have previously impersonated Microsoft tech support to target government employees.
Security Mechanism:
– Automatic verification of first-time external sender messages
– Two-step confirmation process for accepting potentially risky messages
– Audit log tracking for detected phishing attempts
– Integration with existing Teams security infrastructure
Interim Security Recommendations:
– Disable external access if not required
– Implement domain allowlisting for necessary external communications
– Update relevant documentation
– Educate users about new security warnings
The feature’s rollout addresses security concerns across Teams’ vast user base of over 320 million monthly active users in 181 markets. This implementation represents a significant step in Microsoft’s ongoing efforts to enhance platform security and protect users from sophisticated phishing attempts.