PowerShell Scheduled Task Creation via ScriptBlock Logging

Identifies PowerShell script blocks that create and register scheduled tasks using TaskScheduler cmdlets or CIM WMI method calls.

FreeReviewedSigma · Medium · v2

Product: windows
Category: ps_script
Author: frack113 (SigmaHQ), DRL 1.1
Published: 2021-12-28
Updated: 2026-07-31

Analysis Detection

ATT&CK techniques

Execution → Priv Esc

Recon
Resource Dev
Initial Access
Execution
- T1053.005Scheduled Task
Persistence
- T1053.005Scheduled Task
Priv Esc
- T1053.005Scheduled Task
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule identifies PowerShell script activity that constructs and registers Windows Scheduled Tasks by matching common cmdlets such as New-ScheduledTaskAction, New-ScheduledTaskTrigger, and Register-ScheduledTask. It also catches CIM-based scheduled task creation by looking for Invoke-CimMethod targeting PS_ScheduledTask in the TaskScheduler WMI namespace. These behaviors matter because scheduled tasks can enable recurring or initial execution of attacker-controlled code for persistence or execution staging. The detection relies on Script Block Logging telemetry containing the relevant command and parameter strings.

Reporting behind it

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PowerShell Scheduled Task Creation via ScriptBlock Logging

Pivot detection · T1053.005 · 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-scheduled-task-creation-via-scheduledtasks-cmdlets-and-cim-wmi-calls--363eccc0

title: PowerShell Scheduled Task Creation via ScriptBlock Logging
id: abc4cf9d-59b3-436a-aa7c-c60c4eca8ec4
status: test
description: This rule identifies PowerShell script activity that constructs and registers Windows Scheduled Tasks by matching common cmdlets such as New-ScheduledTaskAction, New-ScheduledTaskTrigger, and Register-ScheduledTask. It also catches CIM-based scheduled task creation by looking for Invoke-CimMethod targeting PS_ScheduledTask in the TaskScheduler WMI namespace. These behaviors matter because scheduled tasks can enable recurring or initial execution of attacker-controlled code for persistence or execution staging. The detection relies on Script Block Logging telemetry containing the relevant command and parameter strings.
references:
  - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1053.005/T1053.005.md#atomic-test-4---powershell-cmdlet-scheduled-task
  - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1053.005/T1053.005.md#atomic-test-6---wmi-invoke-cimmethod-scheduled-task
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/powershell/powershell_script/posh_ps_cmdlet_scheduled_task.yml
author: frack113, Huntrule Team
date: 2021-12-28
modified: 2025-10-07
tags:
  - attack.privilege-escalation
  - attack.execution
  - attack.persistence
  - attack.t1053.005
logsource:
  product: windows
  category: ps_script
  definition: "Requirements: Script Block Logging must be enabled"
detection:
  selection_cmdlet:
    ScriptBlockText|contains:
      - New-ScheduledTaskAction
      - New-ScheduledTaskTrigger
      - New-ScheduledTaskPrincipal
      - New-ScheduledTaskSettingsSet
      - New-ScheduledTask
      - Register-ScheduledTask
  selection_cimmethod:
    ScriptBlockText|contains|all:
      - Invoke-CimMethod
      - -ClassName
      - PS_ScheduledTask
      - -NameSpace
      - Root\Microsoft\Windows\TaskScheduler
  filter_main_legitimate_scripts:
    ScriptBlockText|contains|all:
      - Microsoft.PowerShell.Core\Export-ModuleMember
      - Microsoft.Management.Infrastructure.CimInstance
      - __cmdletization_methodParameter
  condition: 1 of selection_* and not 1 of filter_main_*
falsepositives:
  - Unknown
level: medium
license: DRL-1.1
related:
  - id: 363eccc0-279a-4ccf-a3ab-24c2e63b11fb
    type: derived

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