Azure Activity Logs: Alert Suppression Rule Write Operations
Flags when an Azure alert suppression rule is created via the security alerts suppression write operation.
FreeReviewedSigma · Medium · v5
- Product
- azure
- Service
- activitylogs
- Author
- Austin Songer (SigmaHQ), DRL 1.1
- Published
- 2021-08-16
- Updated
- 2026-07-31
What it detects
This rule flags creation of Azure Security alert suppression rules by matching activity log events where operationName is MICROSOFT.SECURITY/ALERTSSUPPRESSIONRULES/WRITE. Attackers may use this capability to reduce visibility by suppressing alerts tied to specific conditions. The detection relies on Azure Activity Logs telemetry and the operationName field indicating the suppression rule write action.
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-activity-logs-alert-suppression-rule-created-92cc3e5d
title: "Azure Activity Logs: Alert Suppression Rule Write Operations"
id: 94fcf510-1d29-4c20-9bb1-87752d811232
status: test
description: This rule flags creation of Azure Security alert suppression rules by matching activity log events where operationName is MICROSOFT.SECURITY/ALERTSSUPPRESSIONRULES/WRITE. Attackers may use this capability to reduce visibility by suppressing alerts tied to specific conditions. The detection relies on Azure Activity Logs telemetry and the operationName field indicating the suppression rule write action.
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_suppression_rule_created.yml
author: Austin Songer, Huntrule Team
date: 2021-08-16
modified: 2022-08-23
tags:
- attack.impact
logsource:
product: azure
service: activitylogs
detection:
selection:
operationName: MICROSOFT.SECURITY/ALERTSSUPPRESSIONRULES/WRITE
condition: selection
falsepositives:
- Suppression Rule being created may be performed by a system administrator.
- Verify whether the user identity, user agent, and/or hostname should be making changes in your environment.
- Suppression Rule created 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: 92cc3e5d-eb57-419d-8c16-5c63f325a401
type: derived