Disinfectant was a popular antivirus software program for the classic Mac OS . It was Originally released as freeware by John Norstad in the spring of 1989.  Disinfectant has featured system extension That Would detect virus infections and an app with users qui Could scan for and remove viruses.  New versions of Disinfectant would be further released to detect additional viruses.  Bob LeVitus praised and recommended Disinfectant in 1992.  In May 1998, Norstad retired Disinfectant, citing the new danger posed by macro viruses, which Disinfectant did not detect, and the inability of a single individual to maintain a program that caught all of them.  
- Jump up^ Norstad, John (1998-10-11). “Disinfectant Retired” . Retrieved 2016-04-06 .
- ^ Jump up to:a b Duncan, Geoff (1997-07-14). “Disinfectant 3.7.1” . TidBITS . Retrieved 2016-04-06 .
- ^ Jump up to:a b c d e Anbinder, Mark H. (1998-05-11). “John Norstad Retires Disinfectant” . TidBITS . Retrieved 2016-04-06 .
- ^ Jump up to:a b “Disinfectant: Macintosh Anti-Virual Utility” . Apple Inc. 2012-02-18 . Retrieved 2016-04-06 .
- ^ Jump up to:a b Borrell, Jerry (1991-01-01). Macworld Read Me First Book . IDG Books . p. 219.
- Jump up^ LeVitus, Bob (1992). Dr. Macintosh’s Guide to the On-Line Universe . Addison-Wesley . p. 270.