Detection rules › Panther

Azure Storage Account Shared Key Access Enabled

Severity
medium
Log types
Azure.MonitorActivity
Tags
Persistence, Account Manipulation
Reference
https://orca.security/resources/blog/azure-shared-key-authorization-exploitation/
Source
github.com/panther-labs/panther-analysis

Detects when an existing Azure storage account's shared key access is enabled (allowSharedKeyAccess: true). Shared key access uses storage account keys for authentication, which is less secure than Azure AD-based authentication.

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1098 Account Manipulation

Rule body yaml

AnalysisType: rule
Filename: azure_storage_account_key_access_enabled.py
RuleID: "Azure.MonitorActivity.StorageAccount.SharedKeyAccessEnabled"
DisplayName: "Azure Storage Account Shared Key Access Enabled"
Enabled: true
LogTypes:
  - Azure.MonitorActivity
Severity: Medium
Description: >
  Detects when an existing Azure storage account's shared key access is enabled (allowSharedKeyAccess: true).
  Shared key access uses storage account keys for authentication, which is less secure than Azure AD-based authentication.
Reports:
  MITRE ATT&CK:
    - TA0006:T1098 # Persistence: Account Manipulation
Tags:
  - Persistence
  - Account Manipulation
Runbook: |
  1. Query Azure Monitor Activity logs for all storage account operations by the callerIpAddress in the 6 hours before and after this alert to identify patterns
  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 storage account configuration changes or data access events from the same user or IP in the past 7 days to assess risk
Reference: https://orca.security/resources/blog/azure-shared-key-authorization-exploitation/
SummaryAttributes:
  - resourceId
  - callerIpAddress
  - correlationId
Tests:
  - Name: Shared Key Access Enabled
    ExpectedResult: true
    Log:
      {
        "time": "2024-12-17T10:30:00.0000000Z",
        "resourceId": "/subscriptions/12345678-1234-1234-1234-123456789abc/resourceGroups/myresourcegroup/providers/Microsoft.Storage/storageAccounts/mystorageaccount",
        "operationName": "Microsoft.Storage/storageAccounts/write",
        "operationVersion": "2021-04-01",
        "category": "Administrative",
        "resultType": "Success",
        "resultSignature": "200",
        "durationMs": 1523,
        "callerIpAddress": "1.1.1.1",
        "correlationId": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
        "identity": {
          "claims": {
            "name": "denethor@lotr.com"
          }
        },
        "level": "Informational",
        "location": "eastus",
        "properties": {
          "requestbody": "{\"properties\":{\"allowSharedKeyAccess\":true}}"
        },
        "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.Storage/storageAccounts/prodstorage",
        "operationName": "microsoft.storage/storageaccounts/write",
        "operationVersion": "2021-04-01",
        "category": "Administrative",
        "resultType": "Succeeded",
        "callerIpAddress": "1.2.3.4",
        "correlationId": "f9e8d7c6-b5a4-3210-9876-fedcba098765",
        "properties": {
          "requestbody": "{\"properties\":{\"allowSharedKeyAccess\":true}}"
        },
        "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.Storage/storageAccounts/mystorageaccount",
        "operationName": "Microsoft.Storage/storageAccounts/delete",
        "operationVersion": "2021-04-01",
        "category": "Administrative",
        "resultType": "Success",
        "callerIpAddress": "3.3.3.3",
        "correlationId": "d4e5f6a7-b8c9-0123-def0-444444444444",
        "tenantId": "87654321-4321-4321-4321-111111111111"
      }

Detection logic

Condition

operationName eq "MICROSOFT.STORAGE/STORAGEACCOUNTS/WRITE"
resultType in ["Success", "Succeeded"]

This rule also runs imperative logic the parser cannot express as a filter; the conditions above are the structured part it could extract.

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.STORAGE/STORAGEACCOUNTS/WRITE
resultTypein
  • Succeeded
  • Success