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

queryFrequency: 1d
entityMappings:
- fieldMappings:
  - columnName: Computer
    identifier: FullName
  - columnName: HostName
    identifier: HostName
  - columnName: DnsDomain
    identifier: DnsDomain
  entityType: Host
- fieldMappings:
  - columnName: ClientIP
    identifier: Address
  entityType: IP
triggerThreshold: 0
triggerOperator: gt
severity: Low
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Windows%20Server%20DNS/Analytic%20Rules/DNS_TorProxies.yaml
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),"")
tactics:
- Exfiltration
queryPeriod: 1d
relevantTechniques:
- T1048
requiredDataConnectors:
- connectorId: DNS
  dataTypes:
  - DnsEvents
id: a83ef0f4-dace-4767-bce3-ebd32599d2a0
kind: Scheduled
version: 1.0.3
description: |
  'Identifies IP addresses performing DNS lookups associated with common ToR proxies.'
status: Available
name: DNS events related to ToR proxies

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"
    }
  ]
}