Avast just picked up win32: Horst-BJ in our morning boot-time scan, thank God.
It was in C: Docs and Sets\All Users\Application Data\CanonBJ\IJPrinter\CNMWindows\Canonip6600D\Installer\Inst2\helpkicker.exe

Was it from email or a web page? We keep up to date, and are behind a router.

Thanks,
Jon