Potential Persistence Via Netsh Helper DLL — Sigma Rule

Rule metadata and linked tags

Author: Victor Sergeev, oscd.community. Source status: test; severity: medium. Source dates: 2019-10-25 / 2023-11-28.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 16446c203fa859abf391a7d7ba29782d9dcab9e49da573b92480703301cf12e4

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: Potential Persistence Via Netsh Helper DLL
id: 56321594-9087-49d9-bf10-524fe8479452
related:
    - id: c90362e0-2df3-4e61-94fe-b37615814cb1
      type: similar
    - id: e7b18879-676e-4a0e-ae18-27039185a8e7
      type: similar
status: test
description: |
    Detects the execution of netsh with "add helper" flag in order to add a custom helper DLL. This technique can be abused to add a malicious helper DLL that can be used as a persistence proxy that gets called when netsh.exe is executed.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1546.007/T1546.007.md
    - https://github.com/outflanknl/NetshHelperBeacon
    - https://web.archive.org/web/20160928212230/https://www.adaptforward.com/2016/09/using-netshell-to-execute-evil-dlls-and-persist-on-a-host/
author: Victor Sergeev, oscd.community
date: 2019-10-25
modified: 2023-11-28
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.t1546.007
    - attack.s0108
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - OriginalFileName: 'netsh.exe'
        - Image|endswith: '\netsh.exe'
    selection_cli:
        CommandLine|contains|all:
            - 'add'
            - 'helper'
    condition: all of selection_*
falsepositives:
    - Unknown
level: medium

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1546.007/T1546.007.md
• https://github.com/outflanknl/NetshHelperBeacon
• https://web.archive.org/web/20160928212230/https://www.adaptforward.com/2016/09/using-netshell-to-execute-evil-dlls-and-persist-on-a-host/