Suspicious Scheduled Task Name As GUID — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: medium. Source dates: 2022-10-31 / not supplied.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 6c31607e085bff67a8e7d739a335e9bb12b19422edd0d0da73ec68d2b4cb0a1f

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: Suspicious Scheduled Task Name As GUID
id: ff2fff64-4cd6-4a2b-ba7d-e28a30bbe66b
status: test
description: Detects creation of a scheduled task with a GUID like name
references:
    - https://thedfirreport.com/2022/10/31/follina-exploit-leads-to-domain-compromise/
    - https://thedfirreport.com/2022/02/21/qbot-and-zerologon-lead-to-full-domain-compromise/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-10-31
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.execution
    - attack.t1053.005
logsource:
    product: windows
    category: process_creation
detection:
    selection_img:
        Image|endswith: '\schtasks.exe'
        CommandLine|contains: '/Create '
    selection_tn:
        CommandLine|contains:
            # Can start with single or double quote
            - '/TN "{'
            - "/TN '{"
            - "/TN {"
    selection_end:
        CommandLine|contains:
            # Ending of the name to avoid possible FP in the rest of the commandline
            - '}"'
            - "}'"
            - '} '
    condition: all of selection_*
falsepositives:
    - Legitimate software naming their tasks as GUIDs
level: medium

Original YAML and metadata in JSON

False positives

• Legitimate software naming their tasks as GUIDs

Source references

• https://thedfirreport.com/2022/10/31/follina-exploit-leads-to-domain-compromise/
• https://thedfirreport.com/2022/02/21/qbot-and-zerologon-lead-to-full-domain-compromise/