Application ID URI Changed

AuditLogs
  | where Category == "ApplicationManagement"
  | where OperationName has_any ("Update Application", "Update Service principal")
  | extend appName = tostring(parse_json(tostring(InitiatedBy.app)).displayName)
  | extend UPN = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)
  | extend UpdatedBy = iif(isnotempty(appName), appName, UPN)
  | extend mod_props = TargetResources[0].modifiedProperties
  | extend AppName = tostring(TargetResources[0].displayName)
  | mv-expand mod_props
  | where mod_props.displayName has "AppIdentifierUri"
  | extend OldURI = tostring(mod_props.oldValue)
  | extend NewURI = tostring(mod_props.newValue)
  | project-reorder TimeGenerated, OperationName, AppName, OldURI, NewURI, UpdatedBy

severity: Medium
triggerThreshold: 0
metadata:
  source:
    kind: Community
  support:
    tier: Community
  categories:
    domains:
    - Security - Others
  author:
    name: Pete Bryan
queryFrequency: 1d
requiredDataConnectors:
- connectorId: AzureActiveDirectory
  dataTypes:
  - AuditLogs
id: 9fb2ee72-959f-4c2b-bc38-483affc539e4
version: 1.0.1
name: Application ID URI Changed
kind: Scheduled
query: |
  AuditLogs
    | where Category == "ApplicationManagement"
    | where OperationName has_any ("Update Application", "Update Service principal")
    | extend appName = tostring(parse_json(tostring(InitiatedBy.app)).displayName)
    | extend UPN = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)
    | extend UpdatedBy = iif(isnotempty(appName), appName, UPN)
    | extend mod_props = TargetResources[0].modifiedProperties
    | extend AppName = tostring(TargetResources[0].displayName)
    | mv-expand mod_props
    | where mod_props.displayName has "AppIdentifierUri"
    | extend OldURI = tostring(mod_props.oldValue)
    | extend NewURI = tostring(mod_props.newValue)
    | project-reorder TimeGenerated, OperationName, AppName, OldURI, NewURI, UpdatedBy  
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/ApplicationIDURIChanged.yaml
queryPeriod: 1d
relevantTechniques:
- T1078.004
triggerOperator: gt
tactics:
- Persistence
- PrivilegeEscalation
tags:
- AADSecOpsGuide
description: |
  'Detects changes to an Application ID URI.
    Monitor these changes to make sure that they were authorized.
    Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-applications#appid-uri-added-modified-or-removed'  
entityMappings:
- entityType: Account
  fieldMappings:
  - identifier: FullName
    columnName: UpdatedBy
- entityType: URL
  fieldMappings:
  - identifier: Url
    columnName: NewURI

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/9fb2ee72-959f-4c2b-bc38-483affc539e4')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/9fb2ee72-959f-4c2b-bc38-483affc539e4')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01",
      "properties": {
        "displayName": "Application ID URI Changed",
        "description": "'Detects changes to an Application ID URI.\n  Monitor these changes to make sure that they were authorized.\n  Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-applications#appid-uri-added-modified-or-removed'\n",
        "severity": "Medium",
        "enabled": true,
        "query": "AuditLogs\n  | where Category == \"ApplicationManagement\"\n  | where OperationName has_any (\"Update Application\", \"Update Service principal\")\n  | extend appName = tostring(parse_json(tostring(InitiatedBy.app)).displayName)\n  | extend UPN = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)\n  | extend UpdatedBy = iif(isnotempty(appName), appName, UPN)\n  | extend mod_props = TargetResources[0].modifiedProperties\n  | extend AppName = tostring(TargetResources[0].displayName)\n  | mv-expand mod_props\n  | where mod_props.displayName has \"AppIdentifierUri\"\n  | extend OldURI = tostring(mod_props.oldValue)\n  | extend NewURI = tostring(mod_props.newValue)\n  | project-reorder TimeGenerated, OperationName, AppName, OldURI, NewURI, UpdatedBy\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Persistence",
          "PrivilegeEscalation"
        ],
        "techniques": [
          "T1078.004"
        ],
        "alertRuleTemplateName": "9fb2ee72-959f-4c2b-bc38-483affc539e4",
        "customDetails": null,
        "entityMappings": [
          {
            "fieldMappings": [
              {
                "columnName": "UpdatedBy",
                "identifier": "FullName"
              }
            ],
            "entityType": "Account"
          },
          {
            "fieldMappings": [
              {
                "columnName": "NewURI",
                "identifier": "Url"
              }
            ],
            "entityType": "URL"
          }
        ],
        "tags": [
          "AADSecOpsGuide"
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/ApplicationIDURIChanged.yaml",
        "templateVersion": "1.0.1"
      }
    }
  ]
}