Azure Network Firewall Policy Modified or Deleted — Sigma Rule

Rule metadata and linked tags

Author: Austin Songer @austinsonger. Source status: test; severity: medium. Source dates: 2021-09-02 / 2022-08-23.

{
  "product": "azure",
  "service": "activitylogs"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 6572321700dfe2ffe01e0a466d3a9352a910c19433b6c13ae3c2b829821d8950

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Azure Network Firewall Policy Modified or Deleted
id: 83c17918-746e-4bd9-920b-8e098bf88c23
status: test
description: Identifies when a Firewall Policy is Modified or Deleted.
references:
    - https://learn.microsoft.com/en-us/azure/role-based-access-control/resource-provider-operations
author: Austin Songer @austinsonger
date: 2021-09-02
modified: 2022-08-23
tags:
    - attack.impact
    - attack.defense-impairment
    - attack.t1686.001
logsource:
    product: azure
    service: activitylogs
detection:
    selection:
        operationName:
            - MICROSOFT.NETWORK/FIREWALLPOLICIES/WRITE
            - MICROSOFT.NETWORK/FIREWALLPOLICIES/JOIN/ACTION
            - MICROSOFT.NETWORK/FIREWALLPOLICIES/CERTIFICATES/ACTION
            - MICROSOFT.NETWORK/FIREWALLPOLICIES/DELETE
    condition: selection
falsepositives:
    - Firewall Policy being modified or deleted may be performed by a system administrator. Verify whether the user identity, user agent, and/or hostname should be making changes in your environment.
    - Firewall Policy modified or deleted from unfamiliar users should be investigated. If known behavior is causing false positives, it can be exempted from the rule.
level: medium

Original YAML and metadata in JSON

False positives

• Firewall Policy being modified or deleted may be performed by a system administrator. Verify whether the user identity, user agent, and/or hostname should be making changes in your environment.
• Firewall Policy modified or deleted from unfamiliar users should be investigated. If known behavior is causing false positives, it can be exempted from the rule.

Source references

• https://learn.microsoft.com/en-us/azure/role-based-access-control/resource-provider-operations