huntrule

Zeek DNS queries matching Tor proxy and hidden service domains

Alerts on Zeek DNS queries for Tor proxy and onion domain indicators tied to possible anonymized activity.

FreeReviewedSigma · Medium · v2
Product
zeek
Service
dns
Author
Saw Winn Naung , Azure-Sentinel (SigmaHQ), DRL 1.1
Published
2021-08-15
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Exfiltration

  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule flags DNS lookup activity where the queried names match a set of common Tor proxy, hidden service, and related domain suffixes. Such lookups are often used to reach anonymity-network infrastructure, which can support malicious activity by hiding origin and intent. It relies on Zeek DNS telemetry, specifically the DNS query name suffixes observed in DNS logs.

Reporting behind it

Related detections9 linkedT1048 — drag to rearrange
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Suspicious blat Utility Used for SMTP Data Exfiltration
Suspicious Data Exfiltration via WinSCP Command Line in BlackSuit Ransomware
Suspicious Scheduled Task Creation for rclone Exfiltration by The Gentlemen RaaS (via process_creation)
Suspicious DNS Query for Tor Onion Domain
Possible DNS Tunneling via Excessively Long Query Name
Malicious Bulk Data Exfiltration via Rclone (via process_creation)
BITS Payload Downloaded via Commandline (via process_creation)
BITS Payload Downloaded via PowerShell (via powershell)
Zeek DNS queries matching Tor proxy and hidden service domains
Pivot detection · T1048 · 9 related

Changelog

v2
  1. v2
    Candidate ingested via manual entry.2026-07-31
  2. v1
    No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.