Sigma Rule Library

Firewall Rule Deleted Via Netsh.EXE

Detects the removal of a port or application rule in the Windows Firewall configuration using netsh

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Detection logic

selection_img

- Image|endswith: \netsh.exe
- OriginalFileName: netsh.exe

selection_cli

CommandLine|contains|all:
  - firewall
  - "delete "

filter_optional_dropbox

ParentImage|endswith: \Dropbox.exe
CommandLine|contains: name=Dropbox

filter_optional_avast

ParentImage|endswith: \instup.exe
CommandLine|contains: advfirewall firewall delete rule name="Avast Antivirus Admin Client"

Condition

all of selection_* and not 1 of filter_optional_*

Raw YAML

title: Firewall Rule Deleted Via Netsh.EXE
id: 1a5fefe6-734f-452e-a07d-fc1c35bce4b2
status: test
description: Detects the removal of a port or application rule in the Windows Firewall configuration using netsh
references:
    - https://app.any.run/tasks/8bbd5b4c-b82d-4e6d-a3ea-d454594a37cc/
author: frack113
date: 2022-08-14
modified: 2025-10-07
tags:
    - attack.defense-impairment
    - attack.t1686.003
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\netsh.exe'
        - OriginalFileName: 'netsh.exe'
    selection_cli:
        CommandLine|contains|all:
            - 'firewall'
            - 'delete '
    filter_optional_dropbox:
        ParentImage|endswith: '\Dropbox.exe'
        CommandLine|contains: 'name=Dropbox'
    filter_optional_avast:
        ParentImage|endswith: '\instup.exe'
        CommandLine|contains: 'advfirewall firewall delete rule name="Avast Antivirus Admin Client"'
    condition: all of selection_* and not 1 of filter_optional_*
falsepositives:
    - Legitimate administration activity
    - Software installations and removal
level: medium

False positives

  • Legitimate administration activity
  • Software installations and removal

References

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