Windows Security Event 4697: Obfuscated PowerShell Invocation Through Stdin

Alerts on Service creation events where the service command line includes stdin-style PowerShell obfuscation indicators.

FreeReviewedSigma · High · v2

Product: windows
Service: security
Author: Nikita Nazarov, oscd.community (SigmaHQ), DRL 1.1
Published: 2020-10-12
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 service installation events (Event ID 4697) where the service file command line appears to include PowerShell invocation patterns combined with standard input style input placeholders. Attackers often use obfuscated PowerShell to evade detection while executing payloads, and abusing stdin can help deliver encoded or hidden commands. The detection relies on telemetry from the Windows Security log (System Security Extension auditing for EID 4697) capturing the service file name/command line string.

Reporting behind it

Related detections9 linkedT1027 — drag to rearrange

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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)

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Windows Security Event 4697: Obfuscated PowerShell Invocation Through Stdin

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.

powershell-obfuscation-via-stdin-using-service-parameter-strings-windows-securit-80b708f3

title: "Windows Security Event 4697: Obfuscated PowerShell Invocation Through Stdin"
id: b6273dd9-0629-400a-9b5c-c9244d90212d
related:
  - id: 487c7524-f892-4054-b263-8a0ace63fc25
    type: derived
  - id: 80b708f3-d034-40e4-a6c8-d23b7a7db3d1
    type: derived
status: test
description: This rule flags Windows service installation events (Event ID 4697) where the service file command line appears to include PowerShell invocation patterns combined with standard input style input placeholders. Attackers often use obfuscated PowerShell to evade detection while executing payloads, and abusing stdin can help deliver encoded or hidden commands. The detection relies on telemetry from the Windows Security log (System Security Extension auditing for EID 4697) capturing the service file name/command line string.
references:
  - https://github.com/SigmaHQ/sigma/issues/1009
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/builtin/security/win_security_invoke_obfuscation_via_stdin_services_security.yml
author: Nikita Nazarov, oscd.community, Huntrule Team
date: 2020-10-12
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:
      - set
      - "&&"
    ServiceFileName|contains:
      - environment
      - invoke
      - ${input)
  condition: selection
falsepositives:
  - Unknown
level: high
license: DRL-1.1

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