Bliss, a Linux "virus"
Bliss has been called a virus for Linux, a common Unix trojan, a virus-like trojan with worm-like features etc, depending on whom you ask. Apparently, the definitions aren't very clear. Here's its story.
The first sighting on the linux-security mailing list happened around January 31, 1997, and Alan Cox replied with this message.
Then, on February 5th, the author of bliss, apparently a nice guy concerned that an earlier alpha version of his code (which was posted on September 29, 1996 to comp.security.unix, alt.comp.virus and comp.os.linux.misc) could still be in use, posted version 0.4.0 to the widely read Usenet newsgrooup comp.security.unix, complete with ample warnings and the prospect of a future (GPL'ed?) source code release.