Tailscale Device key expiring within 7 days

Tailscale_Devices_CL
| where TimeGenerated > ago(6h)
| summarize arg_max(TimeGenerated, *) by DeviceId
| where KeyExpiryDisabled == false
| where isnotnull(Expires)
| where Expires between (now() .. now() + 7d)
| extend DaysToExpiry = datetime_diff('day', Expires, now())
| project TimeGenerated, DeviceName, Hostname, User, Os, DaysToExpiry, Expires, LastSeen

entityMappings:
- entityType: Host
  fieldMappings:
  - identifier: HostName
    columnName: Hostname
- entityType: Account
  fieldMappings:
  - identifier: FullName
    columnName: User
name: 'Tailscale: Device key expiring within 7 days'
kind: Scheduled
triggerOperator: gt
status: Available
queryPeriod: 6h
requiredDataConnectors:
- connectorId: TailscaleCCF
  dataTypes:
  - Tailscale_Devices_CL
tactics:
- InitialAccess
query: |
  Tailscale_Devices_CL
  | where TimeGenerated > ago(6h)
  | summarize arg_max(TimeGenerated, *) by DeviceId
  | where KeyExpiryDisabled == false
  | where isnotnull(Expires)
  | where Expires between (now() .. now() + 7d)
  | extend DaysToExpiry = datetime_diff('day', Expires, now())
  | project TimeGenerated, DeviceName, Hostname, User, Os, DaysToExpiry, Expires, LastSeen
description: |
  Identifies tailnet devices whose machine key expires within the next 7 days and where key expiry is not disabled. Surface proactively so renewal can be scheduled rather than forced during an outage.
severity: Medium
incidentConfiguration:
  groupingConfiguration:
    lookbackDuration: P1D
    enabled: true
    reopenClosedIncident: false
    matchingMethod: AllEntities
  createIncident: true
id: b1a2c3d4-1234-5678-90ab-cdef12345001
triggerThreshold: 0
queryFrequency: 6h
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Tailscale%20%28CCF%29/Analytic%20Rules/TailscaleDeviceKeyExpiringSoon.yaml
version: 1.0.0
relevantTechniques:
- T1078

{
  "$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/b1a2c3d4-1234-5678-90ab-cdef12345001')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/b1a2c3d4-1234-5678-90ab-cdef12345001')]",
      "properties": {
        "alertRuleTemplateName": "b1a2c3d4-1234-5678-90ab-cdef12345001",
        "customDetails": null,
        "description": "Identifies tailnet devices whose machine key expires within the next 7 days and where key expiry is not disabled. Surface proactively so renewal can be scheduled rather than forced during an outage.\n",
        "displayName": "Tailscale: Device key expiring within 7 days",
        "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/TailscaleDeviceKeyExpiringSoon.yaml",
        "query": "Tailscale_Devices_CL\n| where TimeGenerated > ago(6h)\n| summarize arg_max(TimeGenerated, *) by DeviceId\n| where KeyExpiryDisabled == false\n| where isnotnull(Expires)\n| where Expires between (now() .. now() + 7d)\n| extend DaysToExpiry = datetime_diff('day', Expires, now())\n| project TimeGenerated, DeviceName, Hostname, User, Os, DaysToExpiry, Expires, LastSeen\n",
        "queryFrequency": "PT6H",
        "queryPeriod": "PT6H",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "InitialAccess"
        ],
        "techniques": [
          "T1078"
        ],
        "templateVersion": "1.0.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}