Azure Firewall Rule Collection Modified or Deleted via Activity Logs

ATT&CK techniques

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule identifies Azure Firewall changes where rule collections are written to or deleted, covering Application, NAT, and Network rule collections. Such activity can directly alter traffic filtering behavior, enabling attackers or misconfigurations to redirect or disrupt network access. The detection relies on Azure Activity Log events that record operationName values for WRITE and DELETE actions on these specific rule collection resources.

Reporting behind it

Related detections7 linkedT1686.001 — drag to rearrange

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Pivot detection · T1686.001 · 7 related

Changelog

v5

v5
Candidate ingested via manual entry.2026-07-31
v4
Candidate ingested via manual entry.2026-07-31
v3
Candidate ingested via manual entry.2026-07-31
v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

azure-firewall-rule-collections-modified-or-deleted-activity-logs-025c9fe7

title: Azure Firewall Rule Collection Modified or Deleted via Activity Logs
id: b86b5779-9f96-4c98-8951-a67a27b8e50f
status: test
description: This rule identifies Azure Firewall changes where rule collections are written to or deleted, covering Application, NAT, and Network rule collections. Such activity can directly alter traffic filtering behavior, enabling attackers or misconfigurations to redirect or disrupt network access. The detection relies on Azure Activity Log events that record operationName values for WRITE and DELETE actions on these specific rule collection resources.
references:
  - https://learn.microsoft.com/en-us/azure/role-based-access-control/resource-provider-operations
  - https://github.com/SigmaHQ/sigma/blob/master/rules/cloud/azure/activity_logs/azure_firewall_rule_collection_modified_or_deleted.yml
author: Austin Songer @austinsonger, Huntrule Team
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
license: DRL-1.1
related:
  - id: 025c9fe7-db72-49f9-af0d-31341dd7dd57
    type: derived

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