DNS events related to ToR proxies

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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 Server DNS/Analytic Rules/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

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

ARM

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2023-02-01-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 Server DNS/Analytic Rules/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",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Exfiltration"
        ],
        "techniques": [
          "T1048"
        ],
        "templateVersion": "1.0.3",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}