Tailscale Premium Large outbound transfer over tailnet

let bytesThreshold = 100 * 1024 * 1024;
Tailscale_Network_CL
| where TimeGenerated > ago(1h)
| where HasVirtualTraffic
| mv-expand t = VirtualTraffic
| extend Src = tostring(t.src), Dst = tostring(t.dst), Proto = toint(t.proto), Bytes = tolong(t.txBytes) + tolong(t.rxBytes), Pkts = tolong(t.txPkts) + tolong(t.rxPkts)
| summarize TotalBytes = sum(Bytes), TotalPackets = sum(Pkts) by NodeId, SrcNodeName, SrcUser, DstNodeName, DstUser, Src, Dst, Proto
| where TotalBytes > bytesThreshold
| extend TotalMB = round(TotalBytes / 1024.0 / 1024.0, 2)
| order by TotalBytes desc

incidentConfiguration:
  groupingConfiguration:
    lookbackDuration: PT5H
    reopenClosedIncident: false
    matchingMethod: AllEntities
    enabled: true
  createIncident: true
name: 'Tailscale Premium: Large outbound transfer over tailnet'
triggerOperator: gt
query: |
  let bytesThreshold = 100 * 1024 * 1024;
  Tailscale_Network_CL
  | where TimeGenerated > ago(1h)
  | where HasVirtualTraffic
  | mv-expand t = VirtualTraffic
  | extend Src = tostring(t.src), Dst = tostring(t.dst), Proto = toint(t.proto), Bytes = tolong(t.txBytes) + tolong(t.rxBytes), Pkts = tolong(t.txPkts) + tolong(t.rxPkts)
  | summarize TotalBytes = sum(Bytes), TotalPackets = sum(Pkts) by NodeId, SrcNodeName, SrcUser, DstNodeName, DstUser, Src, Dst, Proto
  | where TotalBytes > bytesThreshold
  | extend TotalMB = round(TotalBytes / 1024.0 / 1024.0, 2)
  | order by TotalBytes desc
queryFrequency: 1h
description: |
  Identifies when a single src-dst pair transfers more than 100 MB over the tailnet within a 1-hour window. Large bursts can indicate data staging, exfiltration, or a misconfigured backup. Requires Tailscale Premium or Enterprise.
id: d2e3f4a5-2b3c-4d5e-6f7a-8b9c0d1e2f3a
triggerThreshold: 0
queryPeriod: 1h
version: 1.0.0
kind: Scheduled
status: Available
severity: Medium
requiredDataConnectors:
- connectorId: TailscalePremiumCCF
  dataTypes:
  - Tailscale_Network_CL
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Tailscale%20%28CCF%29/Analytic%20Rules/TailscalePremiumLargeOutboundTransfer.yaml
relevantTechniques:
- T1041
- T1020
tactics:
- Exfiltration
- Collection
entityMappings:
- fieldMappings:
  - identifier: HostName
    columnName: SrcNodeName
  entityType: Host
- fieldMappings:
  - identifier: HostName
    columnName: DstNodeName
  entityType: Host
- fieldMappings:
  - identifier: FullName
    columnName: SrcUser
  entityType: Account
- fieldMappings:
  - identifier: Address
    columnName: Src
  entityType: IP

{
  "$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/d2e3f4a5-2b3c-4d5e-6f7a-8b9c0d1e2f3a')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/d2e3f4a5-2b3c-4d5e-6f7a-8b9c0d1e2f3a')]",
      "properties": {
        "alertRuleTemplateName": "d2e3f4a5-2b3c-4d5e-6f7a-8b9c0d1e2f3a",
        "customDetails": null,
        "description": "Identifies when a single src-dst pair transfers more than 100 MB over the tailnet within a 1-hour window. Large bursts can indicate data staging, exfiltration, or a misconfigured backup. Requires Tailscale Premium or Enterprise.\n",
        "displayName": "Tailscale Premium: Large outbound transfer over tailnet",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "SrcNodeName",
                "identifier": "HostName"
              }
            ]
          },
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "DstNodeName",
                "identifier": "HostName"
              }
            ]
          },
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "SrcUser",
                "identifier": "FullName"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "Src",
                "identifier": "Address"
              }
            ]
          }
        ],
        "incidentConfiguration": {
          "createIncident": true,
          "groupingConfiguration": {
            "enabled": true,
            "lookbackDuration": "PT5H",
            "matchingMethod": "AllEntities",
            "reopenClosedIncident": false
          }
        },
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Tailscale%20%28CCF%29/Analytic%20Rules/TailscalePremiumLargeOutboundTransfer.yaml",
        "query": "let bytesThreshold = 100 * 1024 * 1024;\nTailscale_Network_CL\n| where TimeGenerated > ago(1h)\n| where HasVirtualTraffic\n| mv-expand t = VirtualTraffic\n| extend Src = tostring(t.src), Dst = tostring(t.dst), Proto = toint(t.proto), Bytes = tolong(t.txBytes) + tolong(t.rxBytes), Pkts = tolong(t.txPkts) + tolong(t.rxPkts)\n| summarize TotalBytes = sum(Bytes), TotalPackets = sum(Pkts) by NodeId, SrcNodeName, SrcUser, DstNodeName, DstUser, Src, Dst, Proto\n| where TotalBytes > bytesThreshold\n| extend TotalMB = round(TotalBytes / 1024.0 / 1024.0, 2)\n| order by TotalBytes desc\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Collection",
          "Exfiltration"
        ],
        "techniques": [
          "T1020",
          "T1041"
        ],
        "templateVersion": "1.0.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}