Detection rules › Sigma

Query Tor Onion Address - DNS Client

Status
test
Severity
high
Log source
product windows, service dns-client
Author
Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects DNS resolution of an .onion address related to Tor routing networks

MITRE ATT&CK coverage

TacticTechniques
Command & ControlT1090.003 Proxy: Multi-hop Proxy

Event coverage

Rule body yaml

title: Query Tor Onion Address - DNS Client
id: 8384bd26-bde6-4da9-8e5d-4174a7a47ca2
related:
    - id: b55ca2a3-7cff-4dda-8bdd-c7bfa63bf544
      type: similar
    - id: a8322756-015c-42e7-afb1-436e85ed3ff5
      type: similar
status: test
description: Detects DNS resolution of an .onion address related to Tor routing networks
references:
    - https://www.logpoint.com/en/blog/detecting-tor-use-with-logpoint/
    - https://github.com/Azure/Azure-Sentinel/blob/f99542b94afe0ad2f19a82cc08262e7ac8e1428e/Detections/ASimDNS/imDNS_TorProxies.yaml
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-02-20
modified: 2025-09-12
tags:
    - attack.command-and-control
    - attack.t1090.003
logsource:
    product: windows
    service: dns-client
    definition: 'Requirements: Microsoft-Windows-DNS Client Events/Operational Event Log must be enabled/collected in order to receive the events.'
detection:
    selection:
        EventID: 3008
        QueryName|endswith:
            - '.hiddenservice.net'
            - '.onion.ca'
            - '.onion.cab'
            - '.onion.casa'
            - '.onion.city'
            - '.onion.direct'
            - '.onion.dog'
            - '.onion.glass'
            - '.onion.gq'
            - '.onion.guide'
            - '.onion.in.net'
            - '.onion.ink'
            - '.onion.it'
            - '.onion.link'
            - '.onion.lt'
            - '.onion.lu'
            - '.onion.ly'
            - '.onion.mn'
            - '.onion.network'
            - '.onion.nu'
            - '.onion.pet'
            - '.onion.plus'
            - '.onion.pt'
            - '.onion.pw'
            - '.onion.rip'
            - '.onion.sh'
            - '.onion.si'
            - '.onion.to'
            - '.onion.top'
            - '.onion.ws'
            - '.onion'
            - '.s1.tor-gateways.de'
            - '.s2.tor-gateways.de'
            - '.s3.tor-gateways.de'
            - '.s4.tor-gateways.de'
            - '.s5.tor-gateways.de'
            - '.t2w.pw'
            - '.tor2web.ae.org'
            - '.tor2web.blutmagie.de'
            - '.tor2web.com'
            - '.tor2web.fi'
            - '.tor2web.io'
            - '.tor2web.org'
            - '.tor2web.xyz'
            - '.torlink.co'
    condition: selection
falsepositives:
    - Unlikely
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    EventID: 3008
    QueryName|endswith:
        - '.hiddenservice.net'
        - '.onion.ca'
        - '.onion.cab'
        - '.onion.casa'
        - '.onion.city'
        - '.onion.direct'
        - '.onion.dog'
        - '.onion.glass'
        - '.onion.gq'
        - '.onion.guide'
        - '.onion.in.net'
        - '.onion.ink'
        - '.onion.it'
        - '.onion.link'
        - '.onion.lt'
        - '.onion.lu'
        - '.onion.ly'
        - '.onion.mn'
        - '.onion.network'
        - '.onion.nu'
        - '.onion.pet'
        - '.onion.plus'
        - '.onion.pt'
        - '.onion.pw'
        - '.onion.rip'
        - '.onion.sh'
        - '.onion.si'
        - '.onion.to'
        - '.onion.top'
        - '.onion.ws'
        - '.onion'
        - '.s1.tor-gateways.de'
        - '.s2.tor-gateways.de'
        - '.s3.tor-gateways.de'
        - '.s4.tor-gateways.de'
        - '.s5.tor-gateways.de'
        - '.t2w.pw'
        - '.tor2web.ae.org'
        - '.tor2web.blutmagie.de'
        - '.tor2web.com'
        - '.tor2web.fi'
        - '.tor2web.io'
        - '.tor2web.org'
        - '.tor2web.xyz'
        - '.torlink.co'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
QueryNameends_with
  • .hiddenservice.net corpus 2 (sigma 2)
  • .onion corpus 2 (sigma 2)
  • .onion.ca corpus 2 (sigma 2)
  • .onion.cab corpus 2 (sigma 2)
  • .onion.casa corpus 2 (sigma 2)
  • .onion.city corpus 2 (sigma 2)
  • .onion.direct corpus 2 (sigma 2)
  • .onion.dog corpus 2 (sigma 2)
  • .onion.glass corpus 2 (sigma 2)
  • .onion.gq corpus 2 (sigma 2)
  • .onion.guide
  • .onion.in.net
  • .onion.ink corpus 2 (sigma 2)
  • .onion.it corpus 2 (sigma 2)
  • .onion.link corpus 2 (sigma 2)
  • .onion.lt corpus 2 (sigma 2)
  • .onion.lu corpus 2 (sigma 2)
  • .onion.ly
  • .onion.mn
  • .onion.network
  • .onion.nu corpus 2 (sigma 2)
  • .onion.pet corpus 2 (sigma 2)
  • .onion.plus corpus 2 (sigma 2)
  • .onion.pt
  • .onion.pw
  • .onion.rip corpus 2 (sigma 2)
  • .onion.sh corpus 2 (sigma 2)
  • .onion.si
  • .onion.to corpus 2 (sigma 2)
  • .onion.top corpus 2 (sigma 2)
  • .onion.ws
  • .s1.tor-gateways.de corpus 2 (sigma 2)
  • .s2.tor-gateways.de corpus 2 (sigma 2)
  • .s3.tor-gateways.de corpus 2 (sigma 2)
  • .s4.tor-gateways.de corpus 2 (sigma 2)
  • .s5.tor-gateways.de corpus 2 (sigma 2)
  • .t2w.pw corpus 2 (sigma 2)
  • .tor2web.ae.org corpus 2 (sigma 2)
  • .tor2web.blutmagie.de corpus 2 (sigma 2)
  • .tor2web.com corpus 2 (sigma 2)
  • .tor2web.fi corpus 2 (sigma 2)
  • .tor2web.io corpus 2 (sigma 2)
  • .tor2web.org corpus 2 (sigma 2)
  • .tor2web.xyz corpus 2 (sigma 2)
  • .torlink.co corpus 2 (sigma 2)