Linux Auditd: Stop Firewalld, iptables, or UFW Services

Detects stopping firewall services (firewalld/iptables/ufw) on Linux via auditd service-stop events.

FreeReviewedSigma · High · v3

Product: linux
Service: auditd
Author: Pawel Mazur (SigmaHQ), DRL 1.1
Published: 2022-01-22
Updated: 2026-07-31

ATT&CK techniques

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule identifies attempts to disable host firewall enforcement by stopping the firewalld, iptables, or UFW services. Attackers often impair defenses to reduce network filtering and make it easier to reach internal or external targets. It relies on auditd service stop telemetry that records unit stop events for these specific firewall components.

Reporting behind it

Related detections9 linkedT1686 — drag to rearrange

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Suspicious Outbound Firewall Block Rule Added via Netsh Advfirewall

Malicious Windows Firewall Disable via Netsh

OpenSSH Server Firewall Configuration on Windows - Firewall (via firewall-as)

Suspicious Firewall Rule Added Using PowerShell or CMD (via firewall-as)

Suspicious Firewall Rule Masquerading as CloudExperienceHost via netsh

Suspicious Firewall Rule Masquerading As Windows Update (via process_creation)

Linux Auditd: Stop Firewalld, iptables, or UFW Services

Pivot detection · T1686 · 9 related

Changelog

v3
Candidate ingested via manual entry.2026-07-31
v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

linux-service-stop-firewalld-iptables-or-ufw-firewall-disabled-53059bc0

title: "Linux Auditd: Stop Firewalld, iptables, or UFW Services"
id: a150cac0-a088-4013-9ebb-df787729d0a2
status: test
description: This rule identifies attempts to disable host firewall enforcement by stopping the firewalld, iptables, or UFW services. Attackers often impair defenses to reduce network filtering and make it easier to reach internal or external targets. It relies on auditd service stop telemetry that records unit stop events for these specific firewall components.
references:
  - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1562.004/T1562.004.md
  - https://firewalld.org/documentation/man-pages/firewall-cmd.html
  - https://github.com/SigmaHQ/sigma/blob/master/rules/linux/auditd/service_stop/lnx_auditd_disable_system_firewall.yml
author: Pawel Mazur, Huntrule Team
date: 2022-01-22
tags:
  - attack.defense-impairment
  - attack.t1686
logsource:
  product: linux
  service: auditd
detection:
  selection:
    type: SERVICE_STOP
    unit:
      - firewalld
      - iptables
      - ufw
  condition: selection
falsepositives:
  - Admin activity
level: high
license: DRL-1.1
related:
  - id: 53059bc0-1472-438b-956a-7508a94a91f0
    type: derived

Convert

This rule as a query you can run. Uses no unlock credit.

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