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.

MITRE ATT&CK coverage

TacticTechniques
Defense ImpairmentT1686 Disable or Modify System Firewall

Event coverage

Rule body yaml

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

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
typeeq
  • SERVICE_STOP
uniteq
  • firewalld
  • iptables
  • ufw