Missing Domain Controller Heartbeat

let query_frequency = 15m;
let missing_period = 1h;
//Enter a reference list of hostnames for your DC servers
let DCServersList = dynamic (["DC01.simulandlabs.com","DC02.simulandlabs.com"]);
//Alternatively, a Watchlist can be used
//let DCServersList = _GetWatchlist('HostName-DomainControllers') | project HostName;
Heartbeat
| summarize arg_max(TimeGenerated, *) by Computer
| where Computer in (DCServersList)
//You may specify the OS type of your Domain Controllers
//| where OSType == 'Windows'
| where TimeGenerated between (ago(query_frequency + missing_period) .. ago(missing_period))
| project TimeGenerated, Computer, OSType, Version, ComputerEnvironment, Type, Solutions
| sort by TimeGenerated asc

id: b8b8ba09-1e89-45a1-8bd7-691cd23bfa32
requiredDataConnectors: []
triggerOperator: gt
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/Heartbeat/MissingDCHearbeat.yaml
kind: Scheduled
name: Missing Domain Controller Heartbeat
queryFrequency: 15m
severity: High
query: |
  let query_frequency = 15m;
  let missing_period = 1h;
  //Enter a reference list of hostnames for your DC servers
  let DCServersList = dynamic (["DC01.simulandlabs.com","DC02.simulandlabs.com"]);
  //Alternatively, a Watchlist can be used
  //let DCServersList = _GetWatchlist('HostName-DomainControllers') | project HostName;
  Heartbeat
  | summarize arg_max(TimeGenerated, *) by Computer
  | where Computer in (DCServersList)
  //You may specify the OS type of your Domain Controllers
  //| where OSType == 'Windows'
  | where TimeGenerated between (ago(query_frequency + missing_period) .. ago(missing_period))
  | project TimeGenerated, Computer, OSType, Version, ComputerEnvironment, Type, Solutions
  | sort by TimeGenerated asc  
triggerThreshold: 0
tactics:
- Impact
- DefenseEvasion
entityMappings:
- fieldMappings:
  - columnName: Computer
    identifier: HostName
  entityType: Host
version: 1.0.4
metadata:
  support:
    tier: Community
  source:
    kind: Community
  categories:
    domains:
    - Security - Others
  providers: Microsoft
  author:
    name: Jose Sebastian Canos
queryPeriod: 2h
description: |
    'This detection will go over the heartbeats received from the agents of Domain Controllers over the last hour, and will create alerts if the last heartbeats were received an hour ago.'

{
  "$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/b8b8ba09-1e89-45a1-8bd7-691cd23bfa32')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/b8b8ba09-1e89-45a1-8bd7-691cd23bfa32')]",
      "properties": {
        "alertRuleTemplateName": "b8b8ba09-1e89-45a1-8bd7-691cd23bfa32",
        "customDetails": null,
        "description": "'This detection will go over the heartbeats received from the agents of Domain Controllers over the last hour, and will create alerts if the last heartbeats were received an hour ago.'\n",
        "displayName": "Missing Domain Controller Heartbeat",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "Computer",
                "identifier": "HostName"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/Heartbeat/MissingDCHearbeat.yaml",
        "query": "let query_frequency = 15m;\nlet missing_period = 1h;\n//Enter a reference list of hostnames for your DC servers\nlet DCServersList = dynamic ([\"DC01.simulandlabs.com\",\"DC02.simulandlabs.com\"]);\n//Alternatively, a Watchlist can be used\n//let DCServersList = _GetWatchlist('HostName-DomainControllers') | project HostName;\nHeartbeat\n| summarize arg_max(TimeGenerated, *) by Computer\n| where Computer in (DCServersList)\n//You may specify the OS type of your Domain Controllers\n//| where OSType == 'Windows'\n| where TimeGenerated between (ago(query_frequency + missing_period) .. ago(missing_period))\n| project TimeGenerated, Computer, OSType, Version, ComputerEnvironment, Type, Solutions\n| sort by TimeGenerated asc\n",
        "queryFrequency": "PT15M",
        "queryPeriod": "PT2H",
        "severity": "High",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "DefenseEvasion",
          "Impact"
        ],
        "templateVersion": "1.0.4",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}