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Detection rules › Sigma

Disable System Firewall

Status
test
Severity
high
Log source
product linux, service auditd
Author
Pawel Mazur
Source
github.com/SigmaHQ/sigma

Detects disabling of system firewalls which could be used by adversaries to bypass controls that limit usage of the network.

Known false positives

  • Admin activity

MITRE ATT&CK coverage

TacticTechniques
Defense Impairment

Telemetry coverage

PlatformRecord / event type
Linuxauditd SERVICE_STOP record: Service (daemon) stop

Rule body

title: Disable System Firewall
id: 53059bc0-1472-438b-956a-7508a94a91f0
status: test
description: Detects disabling of system firewalls which could be used by adversaries to bypass controls that limit usage of the network.
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
author: 'Pawel Mazur'
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

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    type: 'SERVICE_STOP'
    unit:
        - 'firewalld'
        - 'iptables'
        - 'ufw'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
typeeq
  • SERVICE_STOP
field:"type" kind:eq value:"SERVICE_STOP"
uniteq
  • firewalld
  • iptables
  • ufw
field:"unit" kind:eq