Azure Firewall Rule Configuration Modified or Deleted via Activity Logs
Flags Azure Activity Log write/delete operations that modify or delete firewall rule groups or rule collection groups.
FreeReviewedSigma · Medium · v5
- Product
- azure
- Service
- activitylogs
- Author
- Austin Songer @austinsonger (SigmaHQ), DRL 1.1
- Published
- 2021-08-08
- Updated
- 2026-07-31
What it detects
This rule identifies Azure Activity Log events where firewall rule configurations are modified or deleted. Such changes can disrupt network access and policy enforcement, making them valuable to attackers seeking to impact connectivity or evade controls. The detection relies on operationName values in Azure Activity Logs covering write and delete operations for firewall policy rule collection groups and rule groups.
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.
azure-firewall-rule-collections-and-groups-modified-or-deleted-via-activity-logs-2a7d64cf
title: Azure Firewall Rule Configuration Modified or Deleted via Activity Logs
id: 5a0cffc6-9865-4aad-b08a-cbdfad810aee
status: test
description: This rule identifies Azure Activity Log events where firewall rule configurations are modified or deleted. Such changes can disrupt network access and policy enforcement, making them valuable to attackers seeking to impact connectivity or evade controls. The detection relies on operationName values in Azure Activity Logs covering write and delete operations for firewall policy rule collection groups and rule groups.
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_rule_modified_or_deleted.yml
author: Austin Songer @austinsonger, Huntrule Team
date: 2021-08-08
modified: 2022-08-23
tags:
- attack.impact
logsource:
product: azure
service: activitylogs
detection:
selection:
operationName:
- MICROSOFT.NETWORK/FIREWALLPOLICIES/RULECOLLECTIONGROUPS/WRITE
- MICROSOFT.NETWORK/FIREWALLPOLICIES/RULECOLLECTIONGROUPS/DELETE
- MICROSOFT.NETWORK/FIREWALLPOLICIES/RULEGROUPS/WRITE
- MICROSOFT.NETWORK/FIREWALLPOLICIES/RULEGROUPS/DELETE
condition: selection
falsepositives:
- Firewall Rule Configuration 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 Rule Configuration 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: 2a7d64cf-81fa-4daf-ab1b-ab80b789c067
type: derived