Suspicious Firewall Rule Added to Open RDP Port 3389 via netsh

ATT&CK techniques

Lateral Movement

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
- T1021.001Remote Desktop Protocol
Collection
C2
Exfiltration
Impact

What it detects

This rule detects netsh adding an advanced firewall rule that opens local port 3389, the Remote Desktop port, observed in a Huntress analysis of exploited RDP misconfigurations. Attackers create this rule to expose RDP through the host firewall after enabling the service. A command-line firewall change opening 3389 during suspicious activity indicates preparation for remote interactive access.

Reporting behind it

Related detections9 linkedT1686 — drag to rearrange

Suspicious Remote Desktop Enablement via Registry fDenyTSConnections and Firewall Rule (via process_creation)

Malicious Remote Desktop Enablement via Netsh

Suspicious RDP Enablement via fDenyTSConnections Registry Modification [Huntress] #2

Suspicious SSH Reverse Tunnel Execution via process_creation

Suspicious VMware PCI Device Disabled via Devcon

Suspicious Remote Desktop Enablement via Registry fDenyTSConnections

Possible Firewall Rule Manipulation via netsh advfirewall by FishMonger

Suspicious netsh Firewall Rule Masquerading as SSTP HTTP

Suspicious Disabling of WinRM Service via sc config

Suspicious Firewall Rule Added to Open RDP Port 3389 via netsh

Pivot detection · T1686 · 9 related

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

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