The CODE-1 virus has been discovered in the United States in November, 1993. It spreads to applications and System files on all Macintosh computers, under System 6 and 7.

The virus renames the boot hard disk to “Trent Saburo” if the Macintosh is restarted on October 31 of any year. It also changes several internal code pointers that may be set by various Extensions, which may lead to system crashes, and failure of some applications to run properly. This may also result in file damage.