FortiGate: Alert on Added Firewall Policy via Event Log

Flags FortiGate events where a firewall policy is added (action Add on firewall.policy).

FreeReviewedSigma · Medium · v2
Product
fortigate
Service
event
Author
Marco Pedrinazzi (@pedrinazziM) (InTheCyber) (SigmaHQ), DRL 1.1
Published
2025-11-01
Updated
2026-07-31
title: "FortiGate: Alert on Added Firewall Policy via Event Log"
id: caf55b7a-eaf9-4388-af08-8468c9dcf5af
status: experimental
description: This rule flags events where a FortiGate firewall policy is added, based on an action value of "Add" tied to the firewall.policy configuration path. Attackers may create new firewall policies to enable unauthorized traffic flows or to bypass existing controls. It relies on FortiGate event telemetry that records configuration changes for firewall policy objects.
references:
  - https://www.fortiguard.com/psirt/FG-IR-24-535
  - https://docs.fortinet.com/document/fortigate/7.6.4/fortios-log-message-reference/398/event
  - https://docs.fortinet.com/document/fortigate/7.6.4/cli-reference/333889629/config-firewall-policy
  - https://docs.fortinet.com/document/fortigate/7.6.4/fortios-log-message-reference/44547/44547-logid-event-config-objattr
  - https://github.com/SigmaHQ/sigma/blob/master/rules/network/fortinet/fortigate/fortinet_fortigate_new_firewall_policy_added.yml
author: Marco Pedrinazzi (@pedrinazziM) (InTheCyber), Huntrule Team
date: 2025-11-01
modified: 2026-05-04
tags:
  - attack.defense-impairment
  - attack.t1686.002
logsource:
  product: fortigate
  service: event
detection:
  selection:
    action: Add
    cfgpath: firewall.policy
  condition: selection
falsepositives:
  - A firewall policy can be added for legitimate purposes.
level: medium
license: DRL-1.1
related:
  - id: f24ab7a8-f09a-4319-82c1-915586aa642b
    type: derived