Azure Network Firewall Policy Modified or Deleted via Activity Logs
Alerts on Azure Activity Log operations that modify or delete Network Firewall Policies.
- Product
- azure
- Service
- activitylogs
- Author
- Austin Songer @austinsonger (SigmaHQ), DRL 1.1
- Published
- 2021-09-02
- Updated
- 2026-07-31
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
Changelog
v5- v5Candidate ingested via manual entry.2026-07-31
- v4Candidate ingested via manual entry.2026-07-31
- v3Candidate ingested via manual entry.2026-07-31
- v2Candidate ingested via manual entry.2026-07-31
- v1No 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.
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