DNS events related to ToR proxies | Microsoft Sentinel Analytic Rules

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Id	a83ef0f4-dace-4767-bce3-ebd32599d2a0
Rulename	DNS events related to ToR proxies
Description	Identifies IP addresses performing DNS lookups associated with common ToR proxies.
Severity	Low
Tactics	Exfiltration
Techniques	T1048
Required data connectors	DNS
Kind	Scheduled
Query frequency	1d
Query period	1d
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Windows%20Server%20DNS/Analytic%20Rules/DNS_TorProxies.yaml
Version	1.0.3
Arm template	a83ef0f4-dace-4767-bce3-ebd32599d2a0.json

KQL

DnsEvents
| where Name contains "."
| where Name has_any ("tor2web.org", "tor2web.com", "torlink.co", "onion.to", "onion.ink", "onion.cab", "onion.nu", "onion.link",
"onion.it", "onion.city", "onion.direct", "onion.top", "onion.casa", "onion.plus", "onion.rip", "onion.dog", "tor2web.fi",
"tor2web.blutmagie.de", "onion.sh", "onion.lu", "onion.pet", "t2w.pw", "tor2web.ae.org", "tor2web.io", "tor2web.xyz", "onion.lt",
"s1.tor-gateways.de", "s2.tor-gateways.de", "s3.tor-gateways.de", "s4.tor-gateways.de", "s5.tor-gateways.de", "hiddenservice.net")
| extend HostName = iff(Computer has '.', substring(Computer,0,indexof(Computer,'.')),Computer)
| extend DnsDomain = iff(Computer has '.', substring(Computer,indexof(Computer,'.')+1),"")

YAML

name: DNS events related to ToR proxies
triggerOperator: gt
query: |
  DnsEvents
  | where Name contains "."
  | where Name has_any ("tor2web.org", "tor2web.com", "torlink.co", "onion.to", "onion.ink", "onion.cab", "onion.nu", "onion.link",
  "onion.it", "onion.city", "onion.direct", "onion.top", "onion.casa", "onion.plus", "onion.rip", "onion.dog", "tor2web.fi",
  "tor2web.blutmagie.de", "onion.sh", "onion.lu", "onion.pet", "t2w.pw", "tor2web.ae.org", "tor2web.io", "tor2web.xyz", "onion.lt",
  "s1.tor-gateways.de", "s2.tor-gateways.de", "s3.tor-gateways.de", "s4.tor-gateways.de", "s5.tor-gateways.de", "hiddenservice.net")
  | extend HostName = iff(Computer has '.', substring(Computer,0,indexof(Computer,'.')),Computer)
  | extend DnsDomain = iff(Computer has '.', substring(Computer,indexof(Computer,'.')+1),"")
queryFrequency: 1d
description: |
  'Identifies IP addresses performing DNS lookups associated with common ToR proxies.'
id: a83ef0f4-dace-4767-bce3-ebd32599d2a0
triggerThreshold: 0
queryPeriod: 1d
version: 1.0.3
kind: Scheduled
status: Available
severity: Low
requiredDataConnectors:
- connectorId: DNS
  dataTypes:
  - DnsEvents
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Windows%20Server%20DNS/Analytic%20Rules/DNS_TorProxies.yaml
relevantTechniques:
- T1048
tactics:
- Exfiltration
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: Computer
  - identifier: HostName
    columnName: HostName
  - identifier: DnsDomain
    columnName: DnsDomain
  entityType: Host
- fieldMappings:
  - identifier: Address
    columnName: ClientIP
  entityType: IP

ARM

{
  "$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/a83ef0f4-dace-4767-bce3-ebd32599d2a0')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/a83ef0f4-dace-4767-bce3-ebd32599d2a0')]",
      "properties": {
        "alertRuleTemplateName": "a83ef0f4-dace-4767-bce3-ebd32599d2a0",
        "customDetails": null,
        "description": "'Identifies IP addresses performing DNS lookups associated with common ToR proxies.'\n",
        "displayName": "DNS events related to ToR proxies",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "Computer",
                "identifier": "FullName"
              },
              {
                "columnName": "HostName",
                "identifier": "HostName"
              },
              {
                "columnName": "DnsDomain",
                "identifier": "DnsDomain"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "ClientIP",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Windows%20Server%20DNS/Analytic%20Rules/DNS_TorProxies.yaml",
        "query": "DnsEvents\n| where Name contains \".\"\n| where Name has_any (\"tor2web.org\", \"tor2web.com\", \"torlink.co\", \"onion.to\", \"onion.ink\", \"onion.cab\", \"onion.nu\", \"onion.link\",\n\"onion.it\", \"onion.city\", \"onion.direct\", \"onion.top\", \"onion.casa\", \"onion.plus\", \"onion.rip\", \"onion.dog\", \"tor2web.fi\",\n\"tor2web.blutmagie.de\", \"onion.sh\", \"onion.lu\", \"onion.pet\", \"t2w.pw\", \"tor2web.ae.org\", \"tor2web.io\", \"tor2web.xyz\", \"onion.lt\",\n\"s1.tor-gateways.de\", \"s2.tor-gateways.de\", \"s3.tor-gateways.de\", \"s4.tor-gateways.de\", \"s5.tor-gateways.de\", \"hiddenservice.net\")\n| extend HostName = iff(Computer has '.', substring(Computer,0,indexof(Computer,'.')),Computer)\n| extend DnsDomain = iff(Computer has '.', substring(Computer,indexof(Computer,'.')+1),\"\")\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Low",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Exfiltration"
        ],
        "techniques": [
          "T1048"
        ],
        "templateVersion": "1.0.3",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}