DragonForce Ransomware Hides C2 Traffic Inside Microsoft Teams Relays — What Security Teams Must Do Now
Backdoor.Turn turns trusted collaboration infrastructure into a covert command channel, blindsiding conventional network defenses.
Published 2026-06-16
# DragonForce Ransomware Hides C2 Traffic Inside Microsoft Teams Relays — What Security Teams Must Do Now
BleepingComputer has reported that the DragonForce ransomware group deployed custom malware tracked as Backdoor.Turn to tunnel command-and-control communications through Microsoft Teams relay infrastructure, effectively disguising malicious traffic as legitimate collaboration traffic.
What Happened
According to the report, DragonForce operators used Backdoor.Turn to route C2 traffic through Microsoft Teams relay servers — the same infrastructure your organization trusts for day-to-day video calls and messaging. Because the traffic originates from and transits through recognized Microsoft endpoints, perimeter firewalls, next-gen proxies, and even many EDR solutions may not flag it as suspicious. The technique is a deliberate abuse of trusted-platform legitimacy, not a vulnerability in Teams itself, but it is exceptionally effective at defeating signature-based detection that relies on known-bad IP addresses or domain reputation.
The immediate risk is dwell time: if C2 traffic blends seamlessly into sanctioned collaboration traffic, attackers can maintain persistent access, exfiltrate data, and stage ransomware payloads for days or weeks before discovery.
Why This Matters for Your Compliance Posture
This attack vector directly stress-tests obligations across every major framework your organization is likely governed by:
- NIS2 mandates that operators of essential and important services detect and respond to threats promptly and report significant incidents within 24–72 hours. A covert Teams-relay C2 channel that evades detection undermines both obligations.
- SOC 2 (CC7) requires continuous monitoring and anomaly detection. Baseline deviation analysis of Teams relay traffic volume and behavior is exactly the control type that would surface Backdoor.Turn — and its absence is an audit finding.
- ISO 27001 (A.8.16 / A.8.23) demands network monitoring and web filtering controls that are capable of identifying unauthorized communication channels, even over trusted services.
- HIPAA breach notification rules are triggered the moment ePHI is reasonably believed to have been accessed by an unauthorized party. A stealthy C2 channel running for weeks before discovery dramatically expands the breach window — and the notification scope.
- PCI DSS v4.0 (Req. 10, 11) requires log review and network intrusion detection that can identify unexpected outbound data flows, including those masquerading as legitimate SaaS traffic.
What You Should Do in the Next 7–30 Days
Within 7 days:
- Query your SIEM or EDR for anomalous process-to-network associations involving Teams relay endpoints, particularly any non-Teams processes initiating connections to `*.teams.microsoft.com` relay addresses.
- Review DNS and proxy logs for unusual volumes or off-hours spikes to Microsoft relay infrastructure.
- Confirm your threat-detection rules include behavioral baselines for collaboration-platform traffic — not just IP reputation feeds.
Within 30 days:
- Implement or validate network behavioral analytics (NBA) that can distinguish sanctioned Teams client traffic from process injection or relay abuse by non-standard binaries.
- Map your detection gap to specific controls in NIS2, SOC 2 CC7, ISO 27001 A.8.16, HIPAA, and PCI DSS Req. 10/11. Document remediation timelines — auditors and regulators increasingly expect evidence of active response, not just policy.
- Run a tabletop exercise scoped specifically to trusted-SaaS C2 scenarios so your incident response runbooks reflect the new reality.
- Ensure your vendor risk register flags Microsoft Teams as a potential abuse vector requiring enhanced monitoring, alongside its role as a sanctioned tool.
Start Closing the Gap Today — Free for 14 Days
RDS GoSOC AI maps your environment against all 16 compliance frameworks — including NIS2, SOC 2, ISO 27001, HIPAA, and PCI DSS — and surfaces detection gaps like the behavioral monitoring blind spots Backdoor.Turn exploits. Start your 14-day free trial at platform.reremrdsgosoc.com/register — every paid feature is unlocked from day one, no credit card required. Once inside, open the User Guide tab for a platform walkthrough, or type your question into the Sage handle to get framework-specific guidance in seconds.