Persistence and Execution at Scale via GPO Scheduled Task — Sigma Rule

Rule metadata and linked tags

Author: Samir Bousseaden. Source status: test; severity: high. Source dates: 2019-04-03 / 2024-09-04.

{
  "product": "windows",
  "service": "security",
  "definition": "The advanced audit policy setting \"Object Access > Audit Detailed File Share\" must be configured for Success/Failure"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: e95a747bea74cb024ce0dd302dbc1c35d5a926f242d0f546d566557881234fb1

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: Persistence and Execution at Scale via GPO Scheduled Task
id: a8f29a7b-b137-4446-80a0-b804272f3da2
status: test
description: Detect lateral movement using GPO scheduled task, usually used to deploy ransomware at scale
references:
    - https://twitter.com/menasec1/status/1106899890377052160
    - https://www.secureworks.com/blog/ransomware-as-a-distraction
    - https://www.elastic.co/guide/en/security/7.17/prebuilt-rule-0-16-1-scheduled-task-execution-at-scale-via-gpo.html
author: Samir Bousseaden
date: 2019-04-03
modified: 2024-09-04
tags:
    - attack.privilege-escalation
    - attack.execution
    - attack.persistence
    - attack.lateral-movement
    - attack.t1053.005
logsource:
    product: windows
    service: security
    definition: 'The advanced audit policy setting "Object Access > Audit Detailed File Share" must be configured for Success/Failure'
detection:
    selection_5136:
        EventID: 5136
        AttributeLDAPDisplayName:
            - 'gPCMachineExtensionNames'
            - 'gPCUserExtensionNames'
        AttributeValue|contains:
            - 'CAB54552-DEEA-4691-817E-ED4A4D1AFC72'
            - 'AADCED64-746C-4633-A97C-D61349046527'
    selection_5145:
        EventID: 5145
        ShareName|endswith: '\SYSVOL' # looking for the string \\*\SYSVOL
        RelativeTargetName|endswith: 'ScheduledTasks.xml'
        AccessList|contains:
            - 'WriteData'
            - '%%4417'
    condition: 1 of selection_*
falsepositives:
    - If the source IP is not localhost then it's super suspicious, better to monitor both local and remote changes to GPO scheduled tasks.
level: high

Original YAML and metadata in JSON

False positives

• If the source IP is not localhost then it's super suspicious, better to monitor both local and remote changes to GPO scheduled tasks.

Source references

• https://twitter.com/menasec1/status/1106899890377052160
• https://www.secureworks.com/blog/ransomware-as-a-distraction
• https://www.elastic.co/guide/en/security/7.17/prebuilt-rule-0-16-1-scheduled-task-execution-at-scale-via-gpo.html