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

triggerOperator: gt
queryFrequency: 15m
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.'
version: 1.0.4
kind: Scheduled
triggerThreshold: 0
requiredDataConnectors: []
queryPeriod: 2h
name: Missing Domain Controller Heartbeat
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/Heartbeat/MissingDCHearbeat.yaml
id: b8b8ba09-1e89-45a1-8bd7-691cd23bfa32
tactics:
- Impact
- DefenseEvasion
metadata:
  categories:
    domains:
    - Security - Others
  providers: Microsoft
  support:
    tier: Community
  source:
    kind: Community
  author:
    name: Jose Sebastian Canos
severity: High
entityMappings:
- fieldMappings:
  - identifier: HostName
    columnName: Computer
  entityType: Host
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  

{
  "$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"
    }
  ]
}