It had a password protected zip file in an update that hid the payload. That is pretty damn basic and would not have gotten past any retail antivirus program’s heuristic detection.
Chances are that Valve is treated as a ‘trusted publisher’ by Microsoft Defender and thus it bypassed the scan. The malware even payload explicitly checks that no retail antivirus was installed, and that Microsoft Defender was active, prior to attempting to extract and run its payload.
(See comments about for explicit details regarding the malware)
Modern_medicine_isnt@lemmy.world 6 months ago
Clearly it passed thier test. But it was not undetectable.