huntrule

Windows ProtocolHandler.exe Download via Embedded URL Schemes

Flags ProtocolHandler.exe executions with ftp/http/https URLs that indicate automated downloading on Windows.

FreeReviewedSigma · Medium · v1
Product
windows
Category
process_creation
Author
frack113 (SigmaHQ), DRL 1.1
Published
2021-07-13
Updated
2026-07-30
AnalysisDetection

ATT&CK techniques

Defense Evasion

  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 identifies process executions of ProtocolHandler.exe where the command line contains URL schemes (ftp://, http://, or https://), indicating a file download attempt using the ProtocolHandler binary. Attackers can abuse signed Windows components to fetch external content while blending into normal system behavior. The detection relies on Windows process creation telemetry, matching the executable identity and the presence of these URL schemes in the command line.

Reporting behind it

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Windows ProtocolHandler.exe Download via Embedded URL Schemes
Pivot detection · T1218 · 9 related

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