Suspicious propsys.dll Sideload via ComputerDefaults UAC Bypass (via image_load)

ATT&CK techniques

Execution → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
- T1574.001DLL
Persistence
- T1574.001DLL
Priv Esc
- T1548.002Bypass User Account Control
- T1574.001DLL
Defense Evasion
- T1548.002Bypass User Account Control
- T1574.001DLL
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects ComputerDefaults.exe loading propsys.dll from outside the Windows system directories, the DLL sideload and UAC bypass the 8220 Gang chains to elevate and continue its cryptomining deployment. The auto-elevating ComputerDefaults binary is abused to load an attacker propsys.dll placed in a writable path. Detecting this non-system load surfaces the UAC bypass and sideloading step.

Reporting behind it

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Suspicious propsys.dll Sideload via ComputerDefaults UAC Bypass (via image_load)

Pivot detection · T1574.001 · 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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