_zope_security_checker.pyd is a file owned by Zope.org.  Zope is an open source server framework that is used in building portals, intranets, and content managements systems, as well as custom applications.  This file may be on your computer because you have installed Zope software, or interfaced with programs that use it.

.pyd files are files for a specific use of the Python programming language.  PYD wraps the language in a more minimal covering than some other extensions.  For this reason, .pyd files are often “lighter” and quicker than other Python applications.

_zope_security_checker.pyd is not harmful in itself.  However, it may be infected, corrupted, or no longer applicable to the programs you run.  If that is so, then it is just slowing your computer down.  A free scan with ZookaWare PC Cleaner will tell you what programs do and do not belong in your registry.