Microsoft Teams Exploited for Helpdesk Impersonation Attacks

• •Attackers exploit Microsoft Teams to impersonate IT helpdesk staff.
• •The attack chain involves social engineering and legitimate tools like Quick Assist.
• •Organizations must consider external Teams contacts as untrusted to prevent breaches.

Cyber attackers are increasingly using Microsoft Teams to impersonate IT helpdesk staff, employing social engineering tactics to gain remote access to enterprise systems. This method, known as 'cross-tenant helpdesk impersonation,' allows attackers to initiate conversations with employees and convince them to grant access, bypassing traditional phishing defenses. Microsoft has documented a nine-stage attack chain that begins with external Teams chats, leading to the use of legitimate tools like Quick Assist for remote control and data exfiltration. The attackers blend their activities with normal IT operations, making detection challenging. This technique has been observed in multiple incidents, emphasizing the growing risk associated with collaboration platforms. Organizations are urged to treat external Teams contacts as untrusted to mitigate these risks.