New Netsh Helper DLL Registered From A Suspicious Location — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: high. Source dates: 2023-11-28 / not supplied.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: fa6f371c0b7103c6bb8090607c2aea50864d82924844b24f3a9aafa2ca8353dd

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: New Netsh Helper DLL Registered From A Suspicious Location
id: e7b18879-676e-4a0e-ae18-27039185a8e7
related:
    - id: 56321594-9087-49d9-bf10-524fe8479452
      type: similar
    - id: c90362e0-2df3-4e61-94fe-b37615814cb1
      type: similar
status: test
description: |
    Detects changes to the Netsh registry key to add a new DLL value that is located on a suspicious location. This change might be an indication of a potential persistence attempt by adding a malicious Netsh helper
references:
    - https://www.ired.team/offensive-security/persistence/t1128-netsh-helper-dll
    - https://pentestlab.blog/2019/10/29/persistence-netsh-helper-dll/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-11-28
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.t1546.007
logsource:
    category: registry_set
    product: windows
detection:
    selection_target:
        TargetObject|contains: '\SOFTWARE\Microsoft\NetSh'
    selection_folders_1:
        Details|contains:
            - ':\Perflogs\'
            - ':\Users\Public\'
            - ':\Windows\Temp\'
            - '\AppData\Local\Temp\'
            - '\Temporary Internet'
    selection_folders_2:
        - Details|contains|all:
              - ':\Users\'
              - '\Favorites\'
        - Details|contains|all:
              - ':\Users\'
              - '\Favourites\'
        - Details|contains|all:
              - ':\Users\'
              - '\Contacts\'
        - Details|contains|all:
              - ':\Users\'
              - '\Pictures\'
    condition: selection_target and 1 of selection_folders_*
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://www.ired.team/offensive-security/persistence/t1128-netsh-helper-dll
• https://pentestlab.blog/2019/10/29/persistence-netsh-helper-dll/