DNS events related to ToR proxies ASIM DNS Schema

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Id	3fe3c520-04f1-44b8-8398-782ed21435f8
Rulename	DNS events related to ToR proxies (ASIM DNS Schema)
Description	Identifies IP addresses performing DNS lookups associated with common ToR proxies. This analytic rule uses ASIM and supports any built-in or custom source that supports the ASIM DNS schema
Severity	Low
Tactics	Exfiltration
Techniques	T1048
Required data connectors	AzureFirewall CiscoUmbrellaDataConnector Corelight DNS GCPDNSDataConnector InfobloxNIOS NXLogDnsLogs Zscaler
Kind	Scheduled
Query frequency	1d
Query period	1d
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Detections/ASimDNS/imDNS_TorProxies.yaml
Version	1.3.4
Arm template	3fe3c520-04f1-44b8-8398-782ed21435f8.json

KQL

let torProxies=dynamic(["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"]);
_Im_Dns(domain_has_any=torProxies)
| extend HostName = tostring(split(Dvc, ".")[0]), DomainIndex = toint(indexof(Dvc, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(Dvc, DomainIndex + 1), Dvc)
| project-away DomainIndex

YAML

description: |
  'Identifies IP addresses performing DNS lookups associated with common ToR proxies.
  This analytic rule uses [ASIM](https://aka.ms/AboutASIM) and supports any built-in or custom source that supports the ASIM DNS schema'  
kind: Scheduled
tactics:
- Exfiltration
requiredDataConnectors:
- connectorId: DNS
  dataTypes:
  - DnsEvents
- connectorId: AzureFirewall
  dataTypes:
  - AzureDiagnostics
- connectorId: Zscaler
  dataTypes:
  - CommonSecurityLog
- connectorId: InfobloxNIOS
  dataTypes:
  - Syslog
- connectorId: GCPDNSDataConnector
  dataTypes:
  - GCP_DNS_CL
- connectorId: NXLogDnsLogs
  dataTypes:
  - NXLog_DNS_Server_CL
- connectorId: CiscoUmbrellaDataConnector
  dataTypes:
  - Cisco_Umbrella_dns_CL
- connectorId: Corelight
  dataTypes:
  - Corelight_CL
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/ASimDNS/imDNS_TorProxies.yaml
severity: Low
name: DNS events related to ToR proxies  (ASIM DNS Schema)
metadata:
  support:
    tier: Community
  author:
    name: Yaron Fruchtmann
  categories:
    domains:
    - Security - Network
  source:
    kind: Community
triggerThreshold: 0
queryPeriod: 1d
query: |
  let torProxies=dynamic(["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"]);
  _Im_Dns(domain_has_any=torProxies)
  | extend HostName = tostring(split(Dvc, ".")[0]), DomainIndex = toint(indexof(Dvc, '.'))
  | extend HostNameDomain = iff(DomainIndex != -1, substring(Dvc, DomainIndex + 1), Dvc)
  | project-away DomainIndex  
relevantTechniques:
- T1048
id: 3fe3c520-04f1-44b8-8398-782ed21435f8
queryFrequency: 1d
entityMappings:
- entityType: Host
  fieldMappings:
  - columnName: Dvc
    identifier: FullName
  - columnName: HostName
    identifier: HostName
  - columnName: HostNameDomain
    identifier: DnsDomain
- entityType: IP
  fieldMappings:
  - columnName: SrcIpAddr
    identifier: Address
triggerOperator: gt
version: 1.3.4
tags:
- ParentAlert: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/DnsEvents/DNS_TorProxies.yaml
  version: 1.0.0
- Schema: ASIMDns
  SchemaVersion: 0.1.1

ARM