Scheduled Task Executing Payload from Registry — Sigma Rule

Rule metadata and linked tags

Author: X__Junior (Nextron Systems), Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: medium. Source dates: 2023-07-18 / not supplied.

{
  "product": "windows",
  "category": "process_creation"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 96775c1e75af3435310b16833a29a6bbdb400d6ee9a46e445190be884b8f9b0e

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Scheduled Task Executing Payload from Registry
id: 86588b36-c6d3-465f-9cee-8f9093e07798
related:
    - id: c4eeeeae-89f4-43a7-8b48-8d1bdfa66c78
      type: derived
status: test
description: Detects the creation of a schtasks that potentially executes a payload stored in the Windows Registry using PowerShell.
references:
    - https://thedfirreport.com/2022/02/21/qbot-and-zerologon-lead-to-full-domain-compromise/
author: X__Junior (Nextron Systems), Nasreddine Bencherchali (Nextron Systems)
date: 2023-07-18
tags:
    - attack.privilege-escalation
    - attack.execution
    - attack.persistence
    - attack.t1053.005
    - attack.t1059.001
logsource:
    product: windows
    category: process_creation
detection:
    selection_img:
        # schtasks.exe /Create /F /TN "{97F2F70B-10D1-4447-A2F3-9B070C86E261}" /TR "cmd /c start /min \"\" powershell.exe -Command IEX([System.Text.Encoding]::ASCII.GetString([System.Convert]::FromBase64String((Get-ItemProperty -Path HKCU:\SOFTWARE\Pvoeooxf).yzbbvhhdypa))) " /SC MINUTE /MO 30
        - Image|endswith: '\schtasks.exe'
        - OriginalFileName: 'schtasks.exe'
    selection_cli_create:
        CommandLine|contains: '/Create'
    selection_cli_get:
        CommandLine|contains:
            - 'Get-ItemProperty'
            - ' gp ' # Alias
    selection_cli_hive:
        CommandLine|contains:
            - 'HKCU:'
            - 'HKLM:'
            - 'registry::'
            - 'HKEY_'
    filter_main_encoding:
        CommandLine|contains:
            - 'FromBase64String'
            - 'encodedcommand'
    condition: all of selection_* and not 1 of filter_*
falsepositives:
    - Unknown
level: medium

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://thedfirreport.com/2022/02/21/qbot-and-zerologon-lead-to-full-domain-compromise/