The Free On-line Dictionary of Computing (30 December 2018):

antivirus software
antivirus
antivirus program

    Programs to detect and remove computer viruses.  The
   simplest kind scans executable files and boot blocks for a
   list of known viruses.  Others are constantly active,
   attempting to detect the actions of general classes of
   viruses.  antivirus software should always include a regular
   update service allowing it to keep up with the latest viruses
   as they are released.

   (1998-02-25)