John Norstad announced Wednesday that his free Disinfectant anti-virus utility has been retired. Norstad considered updating the utility to combat the recently discovered Autostart-9805 worm (see "Autostart Worm Breaks Malware Silence" in TidBITS-428) but decided to direct his software's loyal users to the various commercial utilities that are available, such as Dr. Solomon's Anti-Virus Toolkit, Virex, or Symantec AntiVirus for Macintosh. Norstad's announcement said, "I made this decision not because of the new Autostart-9805 worm, but rather because of the widespread and dangerous Microsoft macro virus problem." (See TidBITS's article series on macro viruses.) He felt that Disinfectant had been inadequate protection for some time, and continuing to update it would unfairly give users a false sense of security. Norstad began work on Disinfectant in the spring of 1988, and Northwestern University released the first version to the public in March of 1989.