I tried using the Offline Windows Defender in WinPE recently and was unsuccessful; we use the 32bit WinPE for legacy (no EUFI) imaging and I found the 32bit Windows Defender would run inside WinPE, but gave an error because the target OS was 64bit. When I tried the 64bit version of Windows Defender in WinPE, it wouldn't run (citing that a 64bit Windows Defender, could not run on a 32bit OS).
Has anyone had any luck getting an offline virus scanner to run successfully in WinPE? If so, would you mind sharing what you used and how you set it up? For reference, this is the doc I found and followed to run Windows Defender in WinPE. I decided NOT to inject directly into the boot.wim and files and instead mapped a drive back to the core server and copied files and directories to the WinPE drive (X:) after WinPE loaded up on a system. It was a good try, but ultimately, did not work.