Malicious Xctdoor XcLoader Execution via Regsvr32 AppX Path Abuse (via process_creation)
- Product
- windows
- Category
- process_creation
- Author
- HuntRule
- Published
- 2026-09-05
- Updated
- 2026-09-05
ATT&CK techniques
Defense EvasionRecon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule detects regsvr32.exe loading a DLL named settings.lock from the Microsoft MicrosoftOffice365Hub AppX package settings directory. This loader technique is used by the Xctdoor and XcLoader backdoors to execute encrypted payloads from a user AppX path where legitimate COM registration is not expected.
Reporting behind it
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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