This driver is a standard part of the . It is typically invoked when:
Understanding scfilter: The Smart Card Filter Driver Identifier
If this ID appears with a yellow exclamation mark in Device Manager , it usually means Windows cannot find a specific "Minidriver" for the smart card itself, even if the reader driver is working.
Security software (like Norton) sometimes flags scfilter.sys as a threat; however, it is a legitimate Windows system file.