Malicious MSIX Package Execution via App Installer ms-appinstaller Protocol (via process_creation)

ATT&CK techniques

Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
- T1218System Binary Proxy Execution
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects the Windows App Installer binary launching a remote MSIX package through the ms-appinstaller protocol handler and ServerName argument. Financially motivated actors abused this vector to deliver BATLOADER and Cobalt Strike while bypassing SmartScreen.

Reporting behind it

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Malicious MSIX Package Execution via App Installer ms-appinstaller Protocol (via process_creation)

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.

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