INIT 1984 is a computer virus that setup to trigger on Macintosh computers running the classic Mac OS

Mac OS

Mac OS is a series of graphical user interface-based operating systems developed by Apple Inc. for their Macintosh line of computer systems. The Macintosh user experience is credited with popularizing the graphical user interface...

 on any given Friday the 13th

Friday the 13th

Friday the 13th occurs when the thirteenth day of a month falls on a Friday, which superstition holds to be a day of bad luck. In the Gregorian calendar, this day occurs at least once, but at most three times a year...

. The virus was first discovered and isolated in March, 1992. It functions by infecting startup (INIT

Init

init is a program for Unix-based computer operating systems that spawns all other processes. It runs as a daemon and typically has PID 1. The boot loader starts the kernel and the kernel starts init...

) files, then modifying or deleting those files upon startup on Friday the 13th. The virus has a low threat assessment.

Further reading

• Computer Security Resource Center of the National Institute of Standards and Technology
  National Institute of Standards and Technology
  The National Institute of Standards and Technology , known between 1901 and 1988 as the National Bureau of Standards , is a measurement standards laboratory, otherwise known as a National Metrological Institute , which is a non-regulatory agency of the United States Department of Commerce...
  
  , New Macintosh Virus Discovered, March 19, 1992