I guess it would have been helpful to mention how to invoke a Windows Security offline scan from the command line, since you're unable to actually get access to Windows Security in Windows itself.

See this article:  How to Run a Microsoft Defender Offline Scan in Windows 10

If you prefer Powershell, search that article for Option One.  If you prefer Command Prompt, search that article for Option Two.  Those are the step-by-step starting points.

And for those unfamiliar with the phrase, "open an elevated . . .," that means open with administrator privileges.
--

Brian - Windows 10 Pro, 64-Bit, Version 2004, Build 19041
The purpose of education is not to validate ignorance but to overcome it. 
       ~ Lawrence Krauss