ARCV-n

ARCV-n is a large family of viruses authored by the Association of Really Cruel Viruses. A polymorphic virus mutates itself to avoid detection by traditional antivirus and antimalware software. ARCV-n viruses seem to infect COM and/or EXE files rapidly, but do not damage the compromised machine, instead displaying various text messages to the user. An infected file will have the ARCV-n virus appended to the end of it.
The ARCV group of virus writers created close to 100 new viruses in the 3 months they were active, before they were raided by New Scotland Yard in December, January, and February 1993.
Select ARCV viruses were still being circulated at least through 1998, based on virus tables from the Computer Incident Advisory Capability.