Potential Persistence Via Netsh Helper DLL - Registry

Status: test
Severity: medium
Log source: category registry_set, product windows
Author: Anish Bogati
Source: github.com/SigmaHQ/sigma

Detects changes to the Netsh registry key to add a new DLL value. This change might be an indication of a potential persistence attempt by adding a malicious Netsh helper

Known false positives

Legitimate helper added by different programs and the OS

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1546.007` Event Triggered Execution: Netsh Helper DLL
Privilege Escalation	`T1546.007` Event Triggered Execution: Netsh Helper DLL

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 13: RegistryEvent (Value Set)

Rule body

title: Potential Persistence Via Netsh Helper DLL - Registry
id: c90362e0-2df3-4e61-94fe-b37615814cb1
related:
    - id: 56321594-9087-49d9-bf10-524fe8479452
      type: similar
    - id: e7b18879-676e-4a0e-ae18-27039185a8e7
      type: similar
status: test
description: |
    Detects changes to the Netsh registry key to add a new DLL value. 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: Anish Bogati
date: 2023-11-28
modified: 2025-10-08
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.t1546.007
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|contains: '\SOFTWARE\Microsoft\NetSh'
        Details|contains: '.dll'
    filter_main_poqexec:
        Image: 'C:\Windows\System32\poqexec.exe'
        Details:
            - 'ipmontr.dll'
            - 'iasmontr.dll'
            - 'ippromon.dll'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Legitimate helper added by different programs and the OS
level: medium

Stages and Predicates

Stage 0: `condition`

selection and not 1 of filter_main_*

Stage 1: `selection`

selection:
    TargetObject|contains: '\SOFTWARE\Microsoft\NetSh'
    Details|contains: '.dll'

Stage 2: `not filter_main_poqexec`

filter_main_poqexec:
    Image: 'C:\Windows\System32\poqexec.exe'
    Details:
        - 'ipmontr.dll'
        - 'iasmontr.dll'
        - 'ippromon.dll'

Exclusions

The rule actively suppresses these predicates.

Field	Kind	Excluded values	Search
`Details`	eq	`iasmontr.dll`	`excludes:Details` `field:"Details" value:"iasmontr.dll"`
`Details`	eq	`ipmontr.dll`	`excludes:Details` `field:"Details" value:"ipmontr.dll"`
`Details`	eq	`ippromon.dll`	`excludes:Details` `field:"Details" value:"ippromon.dll"`
`Image`	eq	`C:\Windows\System32\poqexec.exe`	`excludes:Image` `field:"Image" value:"C:\Windows\System32\poqexec.exe"`

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Details`	match	`.dll` corpus 5 (sigma 5)	`field:"Details" kind:match value:".dll"`
`TargetObject`	match	`\SOFTWARE\Microsoft\NetSh` corpus 2 (sigma 2)	`field:"TargetObject" kind:match value:"\SOFTWARE\Microsoft\NetSh"`