PowerShell Hidden WindowStyle Indicator in Script Block Text (Windows)

Flags PowerShell script block text indicating WindowStyle set to Hidden, suggesting concealed execution.

FreeReviewedSigma · Medium · v2

Product: windows
Category: ps_script
Author: frack113, Tim Shelton (fp AWS) (SigmaHQ), DRL 1.1
Published: 2021-10-20
Updated: 2026-07-31

ATT&CK techniques

Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
- T1564.003Hidden Window
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags PowerShell script block content that includes the terms "powershell", "WindowStyle", and "Hidden", which can indicate an attempt to run with a concealed window. Attackers may use hidden windows to reduce user visibility while executing actions on a host. The detection relies on Script Block Logging telemetry and matches on ScriptBlockText substring content, excluding matches that contain specific Amazon WorkSpaces-related script paths.

Reporting behind it

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PowerShell Hidden WindowStyle Indicator in Script Block Text (Windows)

Pivot detection · T1564.003 · 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-suspicious-windowstyle-hidden-usage-in-script-block-text-313fbb0a

title: PowerShell Hidden WindowStyle Indicator in Script Block Text (Windows)
id: 07291c94-8c82-4e11-9564-6f1082eb0534
status: test
description: This rule flags PowerShell script block content that includes the terms "powershell", "WindowStyle", and "Hidden", which can indicate an attempt to run with a concealed window. Attackers may use hidden windows to reduce user visibility while executing actions on a host. The detection relies on Script Block Logging telemetry and matches on ScriptBlockText substring content, excluding matches that contain specific Amazon WorkSpaces-related script paths.
references:
  - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1564.003/T1564.003.md
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/powershell/powershell_script/posh_ps_susp_windowstyle.yml
author: frack113, Tim Shelton (fp AWS), Huntrule Team
date: 2021-10-20
modified: 2023-01-03
tags:
  - attack.stealth
  - attack.t1564.003
logsource:
  product: windows
  category: ps_script
  definition: "Requirements: Script Block Logging must be enabled"
detection:
  selection:
    ScriptBlockText|contains|all:
      - powershell
      - WindowStyle
      - Hidden
  filter:
    ScriptBlockText|contains|all:
      - :\Program Files\Amazon\WorkSpacesConfig\Scripts\
      - $PSScriptRoot\Module\WorkspaceScriptModule\WorkspaceScriptModule
  condition: selection and not filter
falsepositives:
  - Unknown
level: medium
license: DRL-1.1
related:
  - id: 313fbb0a-a341-4682-848d-6d6f8c4fab7c
    type: derived

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