huntrule

Suspicious sshd.exe Outbound Connection over SMB Port (via network_connection)

PremiumReviewedSigma · Medium · v1
Product
windows
Category
network_connection
Author
HuntRule
Published
2026-06-03
Updated
2026-08-28
AnalysisDetection

ATT&CK techniques

Lateral Movement

  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule detects the OpenSSH server binary sshd.exe communicating over TCP port 445, an anomalous pairing Stately Taurus used to tunnel SSH sessions across the SMB port to bypass firewall egress restrictions. Running an SSH daemon over the SMB port disguises interactive remote access as normal file-sharing traffic.

Reporting behind it

Related detections9 linkedT1021.002 — drag to rearrange
Malicious Network Share Manipulation via Commandline (via process_creation)
Suspicious Number of Oustanding SMB Requests Increased (via process_creation)
Suspicious SMB Insecure Guest Authentication Activated - Native (via security)
Suspicious PSexec Execution Over SMB Share (via security)
Suspicious Permissions Modification on a Network Share (via security)
Malicious Impacket Atexec Remote Scheduled Task Execution (via process_creation)
Suspicious Lateral Movement by Mounting a Network Share - Net Use - Command (via security)
Malicious Remote Shell Execution via SMB Admin Share (via security)
Suspicious Lateral Movement Detection - Based on "special Groups" Feature (via security)
Suspicious sshd.exe Outbound Connection over SMB Port (via network_connection)
Pivot detection · T1021.002 · 9 related

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