Microsoft warns that threat actors are increasingly abusing external Microsoft Teams collaboration, impersonating IT or helpdesk staff to trick employees into granting remote access and enabling lateral movement for data theft. The attackers leverage legitimate tools and native protocols—including Quick Assist, signed applications, WinRM, and Rclone—to blend malicious activity into normal IT operations, making detection difficult. #MicrosoftTeams #QuickAssist
Keypoints
- Threat actors use external Microsoft Teams chats to impersonate IT or helpdesk personnel and request remote assistance.
- Attackers commonly rely on Quick Assist to gain direct control of employee machines.
- Malicious payloads are executed via trusted signed applications and DLL side-loading to evade detection.
- Attackers use WinRM for lateral movement and tools like Rclone to exfiltrate filtered, high-value data to cloud storage.
- Microsoft advises treating external Teams contacts as untrusted and restricting or monitoring remote assistance tools and WinRM usage.