Sdiagnhost Calling Suspicious Child Process — Sigma Rule

Rule metadata and linked tags

Author: Nextron Systems, @Kostastsale. Source status: test; severity: high. Source dates: 2022-06-01 / 2024-08-23.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: a2aa75dc3117414fb5a678796fec20b4db59f848a073f4515d2c965cbc7463c8

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: Sdiagnhost Calling Suspicious Child Process
id: f3d39c45-de1a-4486-a687-ab126124f744
status: test
description: Detects sdiagnhost.exe calling a suspicious child process (e.g. used in exploits for Follina / CVE-2022-30190)
references:
    - https://twitter.com/nao_sec/status/1530196847679401984
    - https://doublepulsar.com/follina-a-microsoft-office-code-execution-vulnerability-1a47fce5629e
    - https://app.any.run/tasks/713f05d2-fe78-4b9d-a744-f7c133e3fafb/
    - https://app.any.run/tasks/f420d295-0457-4e9b-9b9e-6732be227583/
    - https://app.any.run/tasks/c4117d9a-f463-461a-b90f-4cd258746798/
author: Nextron Systems, @Kostastsale
date: 2022-06-01
modified: 2024-08-23
tags:
    - attack.stealth
    - attack.t1036
    - attack.t1218
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\sdiagnhost.exe'
        Image|endswith:
            # Add more suspicious LOLBins
            - '\powershell.exe'
            - '\pwsh.exe'
            - '\cmd.exe'
            - '\mshta.exe'
            - '\cscript.exe'
            - '\wscript.exe'
            - '\taskkill.exe'
            - '\regsvr32.exe'
            - '\rundll32.exe'
            # - '\csc.exe'   # https://app.any.run/tasks/f420d295-0457-4e9b-9b9e-6732be227583/
            - '\calc.exe'  # https://app.any.run/tasks/f420d295-0457-4e9b-9b9e-6732be227583/
    filter_main_cmd_bits:
        Image|endswith: '\cmd.exe'
        CommandLine|contains: 'bits'
    filter_main_powershell_noprofile:
        Image|endswith: '\powershell.exe'
        CommandLine|endswith:
            - '-noprofile -'
            - '-noprofile'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://twitter.com/nao_sec/status/1530196847679401984
• https://doublepulsar.com/follina-a-microsoft-office-code-execution-vulnerability-1a47fce5629e
• https://app.any.run/tasks/713f05d2-fe78-4b9d-a744-f7c133e3fafb/
• https://app.any.run/tasks/f420d295-0457-4e9b-9b9e-6732be227583/
• https://app.any.run/tasks/c4117d9a-f463-461a-b90f-4cd258746798/