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Windows: Command-Line Use of ms-appinstaller Protocol Handler for File Downloads

Alerts on Windows command lines invoking ms-appinstaller with an http source, indicating potential remote file download behavior.

FreeReviewedSigma · Medium · v1
Product
windows
Category
process_creation
Author
Nasreddine Bencherchali (Nextron Systems), Swachchhanda Shrawan Poudel (SigmaHQ), DRL 1.1
Published
2023-11-09
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 flags Windows process command lines that invoke the ms-appinstaller protocol handler with a source parameter containing an http URL. Attackers can use AppInstaller.EXE via protocol invocation to fetch remote content and store it in an AppInstaller cache location. The detection relies on process creation telemetry and matches the presence of both ms-appinstaller://?source= and http in the command line.

Reporting behind it

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Windows: Command-Line Use of ms-appinstaller Protocol Handler for File Downloads
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.