Azure Network Firewall Policy 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 flags Azure Activity Log events where a Network Firewall Policy is written, joined with action, certificate action changes, or deleted. Attackers may impair defensive controls by modifying or removing firewall policy rules. Detection relies on Azure Activity Log operationName values associated with Firewall Policy write/join/certificate/delete activity and can be correlated with the initiating identity and request context.

Reporting behind it

Related detections7 linkedT1686.001 — drag to rearrange

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Azure Network Firewall Policy Modified or Deleted via Activity Logs

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-network-firewall-policy-modified-or-deleted-via-activity-logs-83c17918

title: Azure Network Firewall Policy Modified or Deleted via Activity Logs
id: e20e1355-cfb9-45f1-a791-97e97d746a9a
status: test
description: This rule flags Azure Activity Log events where a Network Firewall Policy is written, joined with action, certificate action changes, or deleted. Attackers may impair defensive controls by modifying or removing firewall policy rules. Detection relies on Azure Activity Log operationName values associated with Firewall Policy write/join/certificate/delete activity and can be correlated with the initiating identity and request context.
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_network_firewall_policy_modified_or_deleted.yml
author: Austin Songer @austinsonger, Huntrule Team
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
license: DRL-1.1
related:
  - id: 83c17918-746e-4bd9-920b-8e098bf88c23
    type: derived

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