Suspicious Enabling of Remote Desktop via fDenyTSConnections Registry by DeadLock Ransomware

PremiumReviewedSigma · High · v1
Category
registry_set
Author
HuntRule
Published
2026-09-12
Updated
2026-09-12

ATT&CK techniques

Persistence → Lateral Movement
  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Priv Esc

  6. Defense Evasion

  7. Cred Access

  8. Discovery

  9. Collection

  10. C2

  11. Exfiltration

  12. Impact

What it detects

This rule detects modification of the fDenyTSConnections value to zero which enables inbound Remote Desktop connections. The DeadLock ransomware operators enable RDP and open the firewall to facilitate lateral movement. Enabling remote desktop on compromised hosts expands attacker access across the environment.

Related detections9 linkedT1112 — drag to rearrange
Suspicious Remote Desktop Enabled via fDenyTSConnections Registry by Sandworm
Malicious Remote Desktop Enablement via Registry
Enabling RDP service via reg.exe command execution
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Windows reg.exe Used to Modify RDP Terminal Server Registry Values
Malicious Enabling of Restricted Admin Mode via Registry by UAT-8837
Malicious Service DLL Hijack for Persistence via Lotus Blossom
Suspicious Loopback Proxy Server Configured via Registry (via registry_set)
Malicious WDigest Credential Caching Enabled via Registry (via registry_set)
Suspicious Enabling of Remote Desktop via fDenyTSConnections Registry by DeadLock Ransomware
Pivot detection · T1112 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.