DragonForce Hackers Abuse Microsoft Teams Relays to Hide Backdoor.Turn C2 Traffic
Jun 18, 2026
Remote Access Trojan / Ransomware
Threat actors associated with the DragonForce ransomware have been observed using a custom Go-based remote access trojan (RAT) called Backdoor.Turn to conceal command-and-control (C2) traffic inside Microsoft Teams relay infrastructure. According to findings from Broadcom-owned Symantec and Carbon Black, the backdoor was deployed against a major U.S. services firm. The name of the company was not disclosed. "Backdoor.Turn obtains an anonymous Teams visitor token from Microsoft’s Skype-backed identity services, uses a legitimate Microsoft TURN relay to set up the connection, and then runs a QUIC session to the attacker’s real command-and-control (C2) server," the Threat Hunter Team said in a report shared with The Hacker News. "To network defenders, the only traffic they could see was outbound connections to legitimate Microsoft Teams servers. The attackers were on the victim network for between one and two months."
