Detection rules › Panther

Azure Key Vault Permanently Purged

Severity
low
Log types
Azure.MonitorActivity
Tags
Impact, Data Destruction, Inhibit System Recovery, Ransomware
Reference
https://learn.microsoft.com/en-us/azure/key-vault/general/soft-delete-overview
Source
github.com/panther-labs/panther-analysis

Detects when an entire Azure Key Vault is permanently purged. Purging a Key Vault is an irreversible operation that permanently destroys all keys, secrets, and certificates stored within it. This is more destructive than deleting a vault and may indicate ransomware activity or malicious data destruction.

MITRE ATT&CK coverage

Rule body yaml

AnalysisType: rule
Filename: azure_keyvault_purged.py
RuleID: "Azure.MonitorActivity.KeyVault.Purged"
DisplayName: "Azure Key Vault Permanently Purged"
Enabled: true
LogTypes:
  - Azure.MonitorActivity
Severity: Low
Description: >
  Detects when an entire Azure Key Vault is permanently purged.
  Purging a Key Vault is an irreversible operation that permanently destroys all keys, secrets, and certificates stored within it.
  This is more destructive than deleting a vault and may indicate ransomware activity or malicious data destruction.
Reports:
  MITRE ATT&CK:
    - TA0040:T1485 # Impact: Data Destruction
    - TA0040:T1490 # Impact: Inhibit System Recovery
Tags:
  - Impact
  - Data Destruction
  - Inhibit System Recovery
  - Ransomware
Runbook: |
  1. Query Azure MonitorActivity logs for all Key Vault delete and purge operations by the callerIpAddress in the 24 hours before and after this alert to identify if multiple vaults are being targeted
  2. Check if the callerIpAddress is associated with known cloud providers, VPN services, or threat intelligence indicators
  3. Search for other Azure resource deletion or purge operations from the same callerIpAddress in the past 7 days to determine the scope of data destruction activity
Reference: https://learn.microsoft.com/en-us/azure/key-vault/general/soft-delete-overview
SummaryAttributes:
  - resourceId
  - callerIpAddress
  - correlationId
Tests:
  - Name: Key Vault Purged Successfully
    ExpectedResult: true
    Log:
      {
        "time": "2024-12-17T10:30:00.0000000Z",
        "resourceId": "/subscriptions/12345678-1234-1234-1234-123456789abc/providers/Microsoft.KeyVault/locations/eastus/deletedVaults/mykeyvault",
        "operationName": "Microsoft.KeyVault/locations/deletedVaults/purge/action",
        "operationVersion": "2021-04-01",
        "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: Case Insensitive Match
    ExpectedResult: true
    Log:
      {
        "time": "2024-12-17T11:45:00.0000000Z",
        "resourceId": "/subscriptions/12345678-1234-1234-1234-123456789abc/providers/Microsoft.KeyVault/locations/westus/deletedVaults/prodvault",
        "operationName": "microsoft.keyvault/locations/deletedvaults/purge/action",
        "operationVersion": "2021-04-01",
        "category": "Administrative",
        "resultType": "Succeeded",
        "callerIpAddress": "1.2.3.4",
        "correlationId": "f9e8d7c6-b5a4-3210-9876-fedcba098765",
        "location": "eastus",
        "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.KeyVault/vaults/mykeyvault",
        "operationName": "Microsoft.KeyVault/vaults/delete",
        "operationVersion": "2021-04-01",
        "category": "Administrative",
        "resultType": "Success",
        "callerIpAddress": "1.2.3.4",
        "correlationId": "d4e5f6a7-b8c9-0123-def0-234567890123",
        "location": "eastus",
        "tenantId": "87654321-4321-4321-4321-210987654321"
      }

Detection logic

Condition

operationName eq "MICROSOFT.KEYVAULT/LOCATIONS/DELETEDVAULTS/PURGE/ACTION"
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
operationNameeq
  • MICROSOFT.KEYVAULT/LOCATIONS/DELETEDVAULTS/PURGE/ACTION
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
callerIpAddress