Tailscale Unauthorized device connected to control plane

Tailscale_Devices_CL
| where TimeGenerated > ago(1h)
| summarize arg_max(TimeGenerated, *) by DeviceId
| where Authorized == false and ConnectedToControl == true
| project TimeGenerated, DeviceName, Hostname, User, Os, ClientVersion, Created, LastSeen, MachineKey, NodeKey

incidentConfiguration:
  createIncident: true
  groupingConfiguration:
    lookbackDuration: P1D
    reopenClosedIncident: false
    enabled: true
    matchingMethod: AllEntities
entityMappings:
- entityType: Host
  fieldMappings:
  - columnName: Hostname
    identifier: HostName
- entityType: Account
  fieldMappings:
  - columnName: User
    identifier: FullName
query: |
  Tailscale_Devices_CL
  | where TimeGenerated > ago(1h)
  | summarize arg_max(TimeGenerated, *) by DeviceId
  | where Authorized == false and ConnectedToControl == true
  | project TimeGenerated, DeviceName, Hostname, User, Os, ClientVersion, Created, LastSeen, MachineKey, NodeKey
id: a1b2c3d4-5678-9012-3456-789012340042
queryFrequency: 1h
description-detailed: |
  Identifies devices actively connected to the Tailscale control plane (ConnectedToControl=true) but not yet authorized by an admin (Authorized=false). With device approval enabled, persistent entries warrant review; without approval, persistence may indicate a node-key injection attempt.
status: Available
version: 1.0.0
severity: High
relevantTechniques:
- T1078
- T1098
name: 'Tailscale: Unauthorized device connected to control plane'
kind: Scheduled
tactics:
- InitialAccess
- Persistence
requiredDataConnectors:
- dataTypes:
  - Tailscale_Devices_CL
  connectorId: TailscaleCCF
description: Identifies devices actively connected to the Tailscale control plane (ConnectedToControl=true) but not yet authorized by an admin (Authorized=false). Often benign onboarding but can indicate rogue joins.
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Tailscale%20%28CCF%29/Analytic%20Rules/TailscaleUnauthorizedDeviceConnected.yaml
triggerOperator: gt
triggerThreshold: 0
queryPeriod: 1h

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2024-01-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/a1b2c3d4-5678-9012-3456-789012340042')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/a1b2c3d4-5678-9012-3456-789012340042')]",
      "properties": {
        "alertRuleTemplateName": "a1b2c3d4-5678-9012-3456-789012340042",
        "customDetails": null,
        "description": "Identifies devices actively connected to the Tailscale control plane (ConnectedToControl=true) but not yet authorized by an admin (Authorized=false). Often benign onboarding but can indicate rogue joins.",
        "description-detailed": "Identifies devices actively connected to the Tailscale control plane (ConnectedToControl=true) but not yet authorized by an admin (Authorized=false). With device approval enabled, persistent entries warrant review; without approval, persistence may indicate a node-key injection attempt.\n",
        "displayName": "Tailscale: Unauthorized device connected to control plane",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "Hostname",
                "identifier": "HostName"
              }
            ]
          },
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "User",
                "identifier": "FullName"
              }
            ]
          }
        ],
        "incidentConfiguration": {
          "createIncident": true,
          "groupingConfiguration": {
            "enabled": true,
            "lookbackDuration": "P1D",
            "matchingMethod": "AllEntities",
            "reopenClosedIncident": false
          }
        },
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Tailscale%20%28CCF%29/Analytic%20Rules/TailscaleUnauthorizedDeviceConnected.yaml",
        "query": "Tailscale_Devices_CL\n| where TimeGenerated > ago(1h)\n| summarize arg_max(TimeGenerated, *) by DeviceId\n| where Authorized == false and ConnectedToControl == true\n| project TimeGenerated, DeviceName, Hostname, User, Os, ClientVersion, Created, LastSeen, MachineKey, NodeKey\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "High",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "InitialAccess",
          "Persistence"
        ],
        "techniques": [
          "T1078",
          "T1098"
        ],
        "templateVersion": "1.0.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}