Date Discovered 1974
Place of Origin
Source Language
Platform OS 360
File Type(s)
Reported Costs

Rabbit was a program that appeared in 1974. It is likely the third self-replicating program, after Creeper and Reaper.


When Rabbit is executed, it copies itself and sends it twice through the ASP input jobstream. Overtime, so many copies of Rabbit would be running that it would clog the system, making it run slow and making it more difficult to remove the program.


The computers where the Rabbit program was run were slowed down and clogged to the point of being nearly unusable. Cleaning the systems was a long, complicated process. The creator of Rabbit was discharged.

Other FactsEdit

Little information is available on this program. The one first-person account of this program comes from Bill Kennedy, who seems to confirm that a Rabbit program was consciously coded. All other accounts of the program read like urban legends, or read like the Rabbits were not consciously coded, but rather caused by some mistake in the way the operating system handles a program crashing.

Classification for this program is difficult, mostly because there is so little information on Rabbit. "Rabbit", "Wabbit" or "Rabbit job" seems to be generally agreed on as a term for a program that creates multiple copies of itself on a single host computer. It could also probably be described as a worm, as Kennedy's account of Rabbit describes the computer environment in which he witnessed it as "three 360's lashed together", but gives no indication of whether Rabbit infected all three of them.

There was allegedly a hack called "Rabbits" on the Burroughs 5500 computer at the University of Washington Computer Center in 1969. There is no explanation of what kind of "hack" it was, meaning it could simply be a command typed a certain way or a bug in a program. If it was a consciously created program, then it would probably predate Creeper as the first self-replicating program.

Q The Misanthrope wrote a Rabbit-like program in 1972 while in grade 7.


Bill Kennedy. The Risks Digest, Volume 6: Issue 53, Two old viruses. 1988.03.29

Jerry Leichter. The Risks Digest, Volume 6: Issue 54, Old viruses. 1988.04.04

The New Hacker's Dictionary, Wabbit.

Cicatrix Interview with Q The Misanthrope. 1997.09