Azure Firewall Rule Collection Modified or Deleted — Sigma Rule

Rule metadata and linked tags

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

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 0c8b38a802d88e0b153fe0e1550017a73a42a9478ef416550116056e15c64cfb

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 Firewall Rule Collection Modified or Deleted
id: 025c9fe7-db72-49f9-af0d-31341dd7dd57
status: test
description: Identifies when Rule Collections (Application, NAT, and Network) is being modified or deleted.
references:
    - https://learn.microsoft.com/en-us/azure/role-based-access-control/resource-provider-operations
author: Austin Songer @austinsonger
date: 2021-08-08
modified: 2022-08-23
tags:
    - attack.impact
    - attack.defense-impairment
    - attack.t1686.001
logsource:
    product: azure
    service: activitylogs
detection:
    selection:
        operationName:
            - MICROSOFT.NETWORK/AZUREFIREWALLS/APPLICATIONRULECOLLECTIONS/WRITE
            - MICROSOFT.NETWORK/AZUREFIREWALLS/APPLICATIONRULECOLLECTIONS/DELETE
            - MICROSOFT.NETWORK/AZUREFIREWALLS/NATRULECOLLECTIONS/WRITE
            - MICROSOFT.NETWORK/AZUREFIREWALLS/NATRULECOLLECTIONS/DELETE
            - MICROSOFT.NETWORK/AZUREFIREWALLS/NETWORKRULECOLLECTIONS/WRITE
            - MICROSOFT.NETWORK/AZUREFIREWALLS/NETWORKRULECOLLECTIONS/DELETE
    condition: selection
falsepositives:
    - Rule Collections (Application, NAT, and Network) 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.
    - Rule Collections (Application, NAT, and Network) 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

• Rule Collections (Application, NAT, and Network) 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.
• Rule Collections (Application, NAT, and Network) 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