Malicious Remote Command Execution via smbexec Output Redirection Pattern

ATT&CK techniques

Execution → Lateral Movement

Recon
Resource Dev
Initial Access
Execution
- T1569.002Service Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
- T1021.002SMB/Windows Admin Shares
Collection
C2
Exfiltration
Impact

What it detects

This rule detects the Impacket smbexec command pattern where cmd.exe runs a quiet echo redirected to an admin share output file, seen in a Huntress-investigated Komari intrusion for remote command execution over SMB. The tool wraps each command with %COMSPEC% /Q /c and writes results to a __output file on the target C$ share. This structural pattern is highly characteristic of smbexec-based lateral movement.

Reporting behind it

Related detections9 linkedT1021.002 — drag to rearrange

Malicious Lateral Movement via PsExec File-List Target

Malicious PsExec Service Installation via PSEXESVC

Suspicious Lateral Movement via PsExec Service (via process_creation)

Possible PsExec Remote Service Installation with Randomly Named Service (via security)

Windows Named Pipe Creation: Default RemCom Pipe Name

Windows Named Pipe Created for CSExec Default Pipe Name

Windows Registry Service Install Indicators for Cobalt Strike Staging

Windows Service Control Manager Events: Suspicious Service Install Paths used by Cobalt Strike

Windows Security 4697 Alerts for Service Installations Using Cobalt Strike Beacon Payloads

Malicious Remote Command Execution via smbexec Output Redirection Pattern

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.

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