Detection rules › Sigma
Flush Iptables Ufw Chain
Detect use of iptables to flush all firewall rules, tables and chains and allow all network traffic
Known false positives
- Network administrators
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Defense Impairment |
Telemetry coverage
| Platform | Record / event type |
|---|---|
| Linux | Event ID 1: Process Create |
Rule body
title: Flush Iptables Ufw Chain
id: 3be619f4-d9ec-4ea8-a173-18fdd01996ab
status: test
description: Detect use of iptables to flush all firewall rules, tables and chains and allow all network traffic
references:
- https://blogs.blackberry.com/
- https://www.cyberciti.biz/tips/linux-iptables-how-to-flush-all-rules.html
- https://twitter.com/Joseliyo_Jstnk/status/1620131033474822144
author: Joseliyo Sanchez, @Joseliyo_Jstnk
date: 2023-01-18
tags:
- attack.defense-impairment
- attack.t1686
logsource:
product: linux
category: process_creation
detection:
selection_img:
Image|endswith:
- '/iptables'
- '/xtables-legacy-multi'
- '/iptables-legacy-multi'
- '/ip6tables'
- '/ip6tables-legacy-multi'
selection_params:
CommandLine|contains:
- '-F'
- '-Z'
- '-X'
selection_ufw:
CommandLine|contains:
- 'ufw-logging-deny'
- 'ufw-logging-allow'
- 'ufw6-logging-deny'
- 'ufw6-logging-allow'
# - 'ufw-reject-output'
# - 'ufw-track-inputt'
condition: all of selection_*
falsepositives:
- Network administrators
level: medium
Stages and Predicates
Stage 0: condition
all of selection_*Stage 1: selection_img
selection_img:
Image|endswith:
- '/iptables'
- '/xtables-legacy-multi'
- '/iptables-legacy-multi'
- '/ip6tables'
- '/ip6tables-legacy-multi'
Stage 2: selection_params
selection_params:
CommandLine|contains:
- '-F'
- '-Z'
- '-X'
Stage 3: selection_ufw
selection_ufw:
CommandLine|contains:
- 'ufw-logging-deny'
- 'ufw-logging-allow'
- 'ufw6-logging-deny'
- 'ufw6-logging-allow'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
CommandLine | match |
| field:"CommandLine" kind:match |
Image | ends_with |
| field:"Image" kind:ends_with |