Windows Security 4697: cmd.exe Launching Obfuscated PowerShell via Environment Variable Expansion

Alerts on EID 4697 service installation command lines containing obfuscated cmd.exe SET patterns used to execute PowerShell via environment variables.

FreeReviewedSigma · High · v2

Product: windows
Service: security
Author: Jonathan Cheong, oscd.community (SigmaHQ), DRL 1.1
Published: 2020-10-15
Updated: 2026-07-31

Analysis Detection

ATT&CK techniques

Execution → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
- T1059.001PowerShell
Persistence
Priv Esc
Defense Evasion
- T1027Obfuscated Files or Information
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags Windows Security audit events (EventID 4697) where a service is configured with a ServiceFileName that includes cmd.exe execution of SET with string formatting and environment-variable-based obfuscation consistent with PowerShell invocation. Attackers commonly use environment variable expansion and obfuscated command strings to evade detections and hinder analysis while still executing PowerShell. It relies on Security log telemetry for EventID 4697 and string matching within the ServiceFileName for cmd-related execution indicators.

Reporting behind it

Related detections9 linkedT1027 — drag to rearrange

Suspicious PowerShell Invoke-Expression with Replace Obfuscation

Malicious Emmenhtal JavaScript Loader Spawning Encoded PowerShell

Suspicious Python Interpreter Launching Encoded PowerShell via subprocess

Suspicious PS1Bot PowerShell Payload Written to ProgramData (via file_event)

Malicious Non-Interactive Encoded PowerShell Stager (via process_creation)

Suspicious Hidden PowerShell Executing Substring of Dropped File

PowerShell Encoded or Download-Cradle Command Line (via process_creation)

Obfuscated Encoded PowerShell Payload Deployed - PowerShell (via powershell)

Suspicious PowerShell AES Decryption and Reflective Method Invocation in SolarMarker

Windows Security 4697: cmd.exe Launching Obfuscated PowerShell via Environment Variable Expansion

Pivot detection · T1027 · 9 related

Changelog

v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

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

windows-security-eid-4697-cmd-exe-command-using-obfuscated-set-with-f-likely-lau-dcf2db1f

title: "Windows Security 4697: cmd.exe Launching Obfuscated PowerShell via Environment Variable Expansion"
id: 9a4dd2d2-093a-4d38-b2be-ad3fbbb3c753
related:
  - id: 8ca7004b-e620-4ecb-870e-86129b5b8e75
    type: derived
  - id: dcf2db1f-f091-425b-a821-c05875b8925a
    type: derived
status: test
description: This rule flags Windows Security audit events (EventID 4697) where a service is configured with a ServiceFileName that includes cmd.exe execution of SET with string formatting and environment-variable-based obfuscation consistent with PowerShell invocation. Attackers commonly use environment variable expansion and obfuscated command strings to evade detections and hinder analysis while still executing PowerShell. It relies on Security log telemetry for EventID 4697 and string matching within the ServiceFileName for cmd-related execution indicators.
references:
  - https://github.com/SigmaHQ/sigma/issues/1009
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/builtin/security/win_security_invoke_obfuscation_var_services_security.yml
author: Jonathan Cheong, oscd.community, Huntrule Team
date: 2020-10-15
modified: 2022-11-29
tags:
  - attack.stealth
  - attack.t1027
  - attack.execution
  - attack.t1059.001
logsource:
  product: windows
  service: security
  definition: The 'System Security Extension' audit subcategory need to be enabled to log the EID 4697
detection:
  selection:
    EventID: 4697
    ServiceFileName|contains|all:
      - cmd
      - '"set'
      - -f
    ServiceFileName|contains:
      - /c
      - /r
  condition: selection
falsepositives:
  - Unknown
level: high
license: DRL-1.1

Convert

This rule as a query you can run. Uses no unlock credit.

SplunkSPL