Detection rules › Panther

Azure Alert Rules Deleted

Severity
medium
Log types
Azure.MonitorActivity
Tags
Defense Evasion, Impair Defenses, Disable Cloud Logs
Reference
https://learn.microsoft.com/en-us/azure/azure-monitor/alerts/alerts-manage-alert-rules
Source
github.com/panther-labs/panther-analysis

Detects when Azure alert rules are deleted. Deleting alert rules disables security notifications and is a common defense evasion technique.

MITRE ATT&CK coverage

Rule body yaml

AnalysisType: rule
Filename: azure_alert_rules_deleted.py
RuleID: "Azure.MonitorActivity.AlertRules.Deleted"
DisplayName: "Azure Alert Rules Deleted"
Enabled: true
LogTypes:
  - Azure.MonitorActivity
Severity: Medium
Description: >
  Detects when Azure alert rules are deleted. Deleting alert rules disables security notifications and is a common defense evasion technique.
Reports:
  MITRE ATT&CK:
    - TA0005:T1562.008 # Defense Evasion: Impair Defenses - Disable Cloud Logs
Tags:
  - Defense Evasion
  - Impair Defenses
  - Disable Cloud Logs
Runbook: |
  1. Query Azure Monitor Activity logs for all alert rule and notification operations by the callerIpAddress in the 24 hours before and after this alert to identify if multiple alerts are being deleted
  2. Check if the source IP is associated with known cloud providers, VPN services, or corporate network ranges using threat intelligence
  3. Search for other Azure monitoring or security configuration changes from the same user or IP in the past 7 days to assess if this is part of a defense evasion campaign
Reference: https://learn.microsoft.com/en-us/azure/azure-monitor/alerts/alerts-manage-alert-rules
SummaryAttributes:
  - resourceId
  - callerIpAddress
  - correlationId
Tests:
  - Name: Alert Rule Deleted
    ExpectedResult: true
    Log:
      {
        "time": "2024-12-17T10:30:00.0000000Z",
        "resourceId": "/subscriptions/12345678-1234-1234-1234-123456789abc/resourceGroups/myresourcegroup/providers/Microsoft.Insights/alertRules/myalert",
        "operationName": "Microsoft.Insights/alertRules/delete",
        "operationVersion": "2016-03-01",
        "category": "Administrative",
        "resultType": "Success",
        "resultSignature": "200",
        "callerIpAddress": "1.1.1.1",
        "correlationId": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",

        "location": "eastus",
        "tenantId": "87654321-4321-4321-4321-111111111111"
      }
  - Name: Metric Alert Deleted
    ExpectedResult: true
    Log:
      {
        "time": "2024-12-17T11:45:00.0000000Z",
        "resourceId": "/subscriptions/12345678-1234-1234-1234-123456789abc/resourceGroups/prod-rg/providers/Microsoft.Insights/metricAlerts/cpualert",
        "operationName": "Microsoft.Insights/metricAlerts/delete",
        "operationVersion": "2018-03-01",
        "category": "Administrative",
        "resultType": "Succeeded",
        "callerIpAddress": "1.2.3.4",
        "correlationId": "f9e8d7c6-b5a4-3210-9876-fedcba098765",

        "location": "westus",
        "tenantId": "87654321-4321-4321-4321-111111111111"
      }
  - Name: Case Insensitive Match
    ExpectedResult: true
    Log:
      {
        "time": "2024-12-17T12:00:00.0000000Z",
        "resourceId": "/subscriptions/12345678-1234-1234-1234-123456789abc/resourceGroups/security-rg/providers/Microsoft.Insights/metricAlerts/securityalert",
        "operationName": "microsoft.insights/metricalerts/delete",
        "operationVersion": "2018-03-01",
        "category": "Administrative",
        "resultType": "Success",
        "callerIpAddress": "2.2.2.2",
        "correlationId": "c3d4e5f6-a7b8-9012-cdef-222222222222",

        "location": "centralus",
        "tenantId": "87654321-4321-4321-4321-111111111111"
      }
  - Name: Different Operation
    ExpectedResult: false
    Log:
      {
        "time": "2024-12-17T13:30:00.0000000Z",
        "resourceId": "/subscriptions/12345678-1234-1234-1234-123456789abc/resourceGroups/myresourcegroup/providers/Microsoft.Insights/alertRules/myalert",
        "operationName": "Microsoft.Insights/alertRules/write",
        "operationVersion": "2016-03-01",
        "category": "Administrative",
        "resultType": "Success",
        "callerIpAddress": "203.0.113.75",
        "correlationId": "d4e5f6a7-b8c9-0123-def0-234567890123",

        "location": "westeurope",

        tenantId": "87654321-4321-4321-4321-210987654321"
      }

Detection logic

Condition

operationName in ["MICROSOFT.INSIGHTS/ALERTRULES/DELETE", "MICROSOFT.INSIGHTS/METRICALERTS/DELETE"]
resultType in ["Success", "Succeeded"]

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
operationNamein
  • MICROSOFT.INSIGHTS/ALERTRULES/DELETE
  • MICROSOFT.INSIGHTS/METRICALERTS/DELETE
resultTypein
  • Succeeded
  • Success

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

Field
resourceId