The Bulgarian Computer Virus Connection:

In the late 1980s and early 1990s, following the fall of the Eastern Bloc in
1989, a flurry of new computer viruses from Bulgaria showed up on the
computer scene. In those days, Bulgaria's computer technology seemed
desperate and makeshift; The predominant computer system used by young
Bulgarian hackers was the Pravetz 82, which was actually hacked together from
reverse-engineered Apple IIe hardware. Meanwhile, the country's government
couldn't afford Western software, so they simply managed to get one copy and
then copied the program massively, training a whole team of elite programmers
to break copy protection. Surely, it must have been an odd mix, a whole
generation of bright young programmers working with improvised microcomputers
on stolen software. But out of this time period, there came more than just
software cracks; These programmers also apparently practiced their
virus-writing skills. A lot.

During this time period, Bulgaria became the world's notorious hotbed of
virus creation. Particularly in Sofia, the capital city, a whole host of new
viruses were spawned and spread rapidly throughout the world. The most
notorious was Dark Avenger, certainly one of the top 10 most famous viruses
ever written, and which caused an infection of epidemic proportions worldwide
as it was spread by software trading and BBS. Sofia was also the home of the
infamous Virus Exchange BBS, an aptly-named board which was simply a crawling
mass of virus uploading and downloading. Indeed, this BBS was itself
responsible for many of the viruses that came from Bulgaria, because a
requirement for new users joining the board was that they upload a new virus
not already in the BBS's library. Since virtually every known virus was
already there, the only viable option was to write your own new virus so you
would be let into the system.

Despite its presence in the computer world, the Bulgarian virus phenomenon
was curiously under-documented in the media. Although it did make a few
newspaper headlines and magazine articles, it remained largely one of those
things which people talked about but stayed out of the media limelight. It
was finally given a proper magazine article years after the fact, in the
November 1997 issue of Wired Magazine, in an article titled "Heart Of
Darkness", an investigative journey to Bulgaria to interview the people who
were most directly involved in the Bulgarian computer revolution and virus
epidemic.