Microsoft Entra ID Hybrid Health AD FS New Server

AzureActivity
| where CategoryValue =~ 'Administrative'
| where ResourceProviderValue =~ 'Microsoft.ADHybridHealthService'
| where _ResourceId has 'AdFederationService'
| where OperationNameValue =~ 'Microsoft.ADHybridHealthService/services/servicemembers/action'
| extend claimsJson = parse_json(Claims)
| extend AppId = tostring(claimsJson.appid), AccountName = tostring(claimsJson.name), Name = tostring(split(Caller,'@',0)[0]), UPNSuffix = tostring(split(Caller,'@',1)[0])
| project-away claimsJson

OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Activity/Analytic Rules/AADHybridHealthADFSNewServer.yaml
entityMappings:
- fieldMappings:
  - identifier: Name
    columnName: Name
  - identifier: UPNSuffix
    columnName: UPNSuffix
  entityType: Account
- fieldMappings:
  - identifier: Address
    columnName: CallerIpAddress
  entityType: IP
kind: Scheduled
query: |
  AzureActivity
  | where CategoryValue =~ 'Administrative'
  | where ResourceProviderValue =~ 'Microsoft.ADHybridHealthService'
  | where _ResourceId has 'AdFederationService'
  | where OperationNameValue =~ 'Microsoft.ADHybridHealthService/services/servicemembers/action'
  | extend claimsJson = parse_json(Claims)
  | extend AppId = tostring(claimsJson.appid), AccountName = tostring(claimsJson.name), Name = tostring(split(Caller,'@',0)[0]), UPNSuffix = tostring(split(Caller,'@',1)[0])
  | project-away claimsJson  
triggerOperator: gt
version: 2.0.2
queryPeriod: 1d
name: Microsoft Entra ID Hybrid Health AD FS New Server
severity: Medium
relevantTechniques:
- T1578
requiredDataConnectors:
- dataTypes:
  - AzureActivity
  connectorId: AzureActivity
triggerThreshold: 0
tactics:
- DefenseEvasion
queryFrequency: 1d
tags:
- SimuLand
id: 88f453ff-7b9e-45bb-8c12-4058ca5e44ee
status: Available
description: |
  'This detection uses AzureActivity logs (Administrative category) to identify the creation or update of a server instance in an Microsoft Entra ID Hybrid Health AD FS service.
  A threat actor can create a new AD Health ADFS service and create a fake server instance to spoof AD FS signing logs. There is no need to compromise an on-premises AD FS server.
  This can be done programmatically via HTTP requests to Azure. More information in this blog: https://o365blog.com/post/hybridhealthagent/'  

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2023-02-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/88f453ff-7b9e-45bb-8c12-4058ca5e44ee')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/88f453ff-7b9e-45bb-8c12-4058ca5e44ee')]",
      "properties": {
        "alertRuleTemplateName": "88f453ff-7b9e-45bb-8c12-4058ca5e44ee",
        "customDetails": null,
        "description": "'This detection uses AzureActivity logs (Administrative category) to identify the creation or update of a server instance in an Microsoft Entra ID Hybrid Health AD FS service.\nA threat actor can create a new AD Health ADFS service and create a fake server instance to spoof AD FS signing logs. There is no need to compromise an on-premises AD FS server.\nThis can be done programmatically via HTTP requests to Azure. More information in this blog: https://o365blog.com/post/hybridhealthagent/'\n",
        "displayName": "Microsoft Entra ID Hybrid Health AD FS New Server",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "Name",
                "identifier": "Name"
              },
              {
                "columnName": "UPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "CallerIpAddress",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Azure Activity/Analytic Rules/AADHybridHealthADFSNewServer.yaml",
        "query": "AzureActivity\n| where CategoryValue =~ 'Administrative'\n| where ResourceProviderValue =~ 'Microsoft.ADHybridHealthService'\n| where _ResourceId has 'AdFederationService'\n| where OperationNameValue =~ 'Microsoft.ADHybridHealthService/services/servicemembers/action'\n| extend claimsJson = parse_json(Claims)\n| extend AppId = tostring(claimsJson.appid), AccountName = tostring(claimsJson.name), Name = tostring(split(Caller,'@',0)[0]), UPNSuffix = tostring(split(Caller,'@',1)[0])\n| project-away claimsJson\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Medium",
        "status": "Available",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "DefenseEvasion"
        ],
        "tags": [
          "SimuLand"
        ],
        "techniques": [
          "T1578"
        ],
        "templateVersion": "2.0.2",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}