Detection rules › Splunk

Windows Multi hop Proxy TOR Website Query

Author
Teoderick Contreras, Splunk
Source
upstream

The following analytic identifies DNS queries to known TOR proxy websites, such as "*.torproject.org" and "www.theonionrouter.com". It leverages Sysmon EventCode 22 to detect these queries by monitoring DNS query events from endpoints. This activity is significant because adversaries often use TOR proxies to disguise the source of their malicious traffic, making it harder to trace their actions. If confirmed malicious, this behavior could indicate an attempt to obfuscate network traffic, potentially allowing attackers to exfiltrate data or communicate with command and control servers undetected.

MITRE ATT&CK coverage

TacticTechniques
Command & ControlT1071.003 Application Layer Protocol: Mail Protocols

Event coverage

ProviderEvent IDTitle
Sysmon22DNSEvent (DNS query)

Stages and Predicates

Stage 1: search

search EventCode=22 QueryName IN ("*.torproject.org", "www.theonionrouter.com")

Stage 2: stats

stats BY answer, answer_count, dvc, process_exec, process_guid, process_name, query, query_count, reply_code_id, signature, signature_id, src, user_id, vendor_product, QueryName, QueryResults, QueryStatus

Stage 3: search

search

Stage 4: search

search

Stage 5: search

search `macro`

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
EventCodeeq
  • 22 corpus 15 (splunk 15)
QueryNamein
  • "*.torproject.org"
  • "www.theonionrouter.com"