huntrule

Proxy Downloads of Executables and Documents from Suspicious Dynamic DNS Domains

Alerts when proxy traffic downloads common executable or document payload types from a curated list of dynamic DNS hostnames.

FreeReviewedSigma · Medium · v2
Category
proxy
Author
Florian Roth (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2017-11-08
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

C2

  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 proxy requests where the requested URI ends with commonly used file types (executables, scripts, and document formats) and the destination host ends with a selected set of dynamic DNS domain suffixes. Attackers may use dynamic DNS to host or stage payloads while avoiding stable infrastructure indicators. Detection relies on proxy telemetry that includes the request URI extension and the contacted host name.

Reporting behind it

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Suspicious node.exe Execution Spawned by PowerShell
Suspicious Executable Download to Temp Directory via curl on Linux
Suspicious BITSAdmin File Transfer Into ProgramData via Process Creation (via process_creation)
Suspicious DNS Query to Dynamic DNS and Tunneling Providers Abused by RATs
Suspicious PowerShell Download Cradle via IEX and DownloadString (via process_creation)
Suspicious Remote File Download via certutil URLCache (via process_creation)
Proxy Downloads of Executables and Documents from Suspicious Dynamic DNS Domains
Pivot detection · T1105 · 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.