Azure Key Vault Deleted

AnalysisType: rule
Filename: azure_keyvault_deleted.py
RuleID: "Azure.MonitorActivity.KeyVault.Deleted"
DisplayName: "Azure Key Vault Deleted"
Enabled: true
LogTypes:
  - Azure.MonitorActivity
Severity: Medium
Description: >
  Detects when an Azure Key Vault is deleted.
  Key Vault deletion is a destructive operation that may indicate ransomware activity or malicious destruction of secrets and encryption keys.
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 Monitor Activity logs for all Key Vault operations by the callerIpAddress in the 24 hours before this alert to establish if this is part of a larger attack pattern
  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 resource deletions or key/secret access events from the same user or IP in the past 7 days to assess the scope of potential impact
Reference: https://learn.microsoft.com/en-us/azure/key-vault/general/soft-delete-overview
SummaryAttributes:
  - resourceId
  - callerIpAddress
  - correlationId
Tests:
  - Name: Key Vault Deleted
    ExpectedResult: true
    Log:
      {
        "time": "2024-12-17T10:30:00.0000000Z",
        "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",
        "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/resourceGroups/prod-rg/providers/Microsoft.KeyVault/vaults/prodvault",
        "operationName": "microsoft.keyvault/vaults/delete",
        "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/write",
        "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"
      }

# ------ paired body: azure_keyvault_deleted.py ------

from panther_azureactivity_helpers import (
    azure_activity_alert_context,
    azure_activity_success,
    extract_resource_name_from_id,
)

KEYVAULT_DELETE = "MICROSOFT.KEYVAULT/VAULTS/DELETE"


def rule(event):
    return event.get("operationName", "").upper() == KEYVAULT_DELETE and azure_activity_success(
        event
    )


def title(event):
    resource_id = event.get("resourceId", "")
    keyvault = extract_resource_name_from_id(resource_id, "vaults", default="<UNKNOWN_KEYVAULT>")
    caller = event.get("callerIpAddress", default="<UNKNOWN_CALLER>")

    return f"Azure Key Vault deleted [{keyvault}] from [{caller}]"


def alert_context(event):
    context = azure_activity_alert_context(event)

    resource_id = event.get("resourceId", "")
    keyvault_name = extract_resource_name_from_id(resource_id, "vaults", default="")
    if keyvault_name:
        context["keyvault_name"] = keyvault_name

    return context