The Slovakian Virus Scene
Since the death of Bulgaria as the virus centre of the world two or three
years ago, America's recent decline (another story) and the death of
Trident in the Netherlands, the normal places we think of as virus capitals
have moved. Sweden has always been a hotbed of activity, but recently
Taiwan, Australia, Russia and Slovakia have improved in focus.
Slovakia is a small country, being the 'other' half of the former united
czechoslovakia, but it has two virus groups, and a seemingly large interest
in computer viruses.
When the MtE used to be a very popular polymorphic engine, there was
another, not so well known but advanced polymorphic virus called
Slovakia 4.0, the last member of the Slovakia series. It was as good as
the MtE, although it used different techniques. This virus became quite
common in Slovakia. At that time, SCAN only used algorithmic detection
for two things, the MtE and the Slovakias. Also, according to Patricia
Hoffmans VSUM these two were the only strongly polymorphic systems.
Slovakia 4.0 was the last virus this author has created (as far as is
The most famous virus from Slovakia must be OneHalf virus by Vyvojar. It is
the second part of the Explosion series. It has spread all over Europe
and reached the US, thus being clasified as a "common virus". OneHalf
is a light polymorphic COM/EXE/MBR infector. It utilises a special
construction of jumps to distribute the decryptor into 10 pieces all over
the host code (kind of what Commander Bomber does, but in simplified form).
Removing the virus using the popular "FDISK /MBR" usually causes the user
serious trouble as two tracks are encrypted each time the computer is
rebooted and the virus decrypts the data on the fly, so the system becomes
addicted to the virus. This makes it a very popular topic in [anti]virus
Level_3 is the third and final virus in the Explosion series. It implements
EMM1_0 (Explosion's Mutation Machine 1.0), one of today's most advanced
polymorphic engines. There are 2 phases of decryption, one is a linear and
about 700 bytes long, full of conditional jumps (it emulates it's own
code to determine instruction flow). The first phase decrypts the real
decryptor of the virus (which is a simple loop). This is why it can't be
discovered by a simple decryption routine detector. TBAV only catches a few
samples by mistake. The source code can be found in 40hex-14.
Vyvojar (the author of the viruses mentioned above) announced the end of
his virus writing activities because of school graduation and being busy
with different things. This is the end of the career of a virus writing
Although unknown by most, Slovakia is also home to a virus writing group
with three members called the Slovak Virus Laboratories (SVL) who have
written a few quality viruses. The members of the group are JohnyX,
Mengele and The Professor.
The following is a translation of an article they wrote for a popular
This article was originally published in a computer magazine called
PC-REVUE issue 2/95 in a column "VIRUS RADAR", which is dedicated to new
viruses in Slovakia. This article was translated from the Slovak language,
with notes indicated using square brackets.
On the computer, at the end of the year 1994
Dear friends, we wish you all the best in the New Year 1995, in the name of
the Slovak Virus Laboratories (SVL). We have picked this unusual kind of
New Years Greeting (well, we write unusual viruses as well, and one must
admit they're not the worst either), because we are sure that our favourite
VIRUS RADAR will mention it. To show our goodwill, we enclose the source
code of SVL 1.2, which has been discussed recently (we really are the
authors, don't doubt it).
A few words about SVL: we're cheerful guys, who are interested in Fred
Flintstone's philosophy (except our Development Chief, who is only
interested in girls and beer), as well as in writing tasty and juicy
viruses. The group was founded spontaneously about 3 years ago in a bar,
while discussing the advantages of vodka combined with juice against pure
vodka. First we did nothing, but then we started to do some freelance
production. We have achieved several successes, we even got into the
newspapers (we have to mention one successful boot virus, the last one in
former Czechoslovakia [translator's note: Czechoslovakia split into Czech
and Slovakia in 1993; the "successful boot virus" seems to be J&M, which
formats partition table on November 15, although I assume that the virus
comes from Czech originally]).
Also in August we managed to do something, partly because one of our
irresponsible members forgot to change the text in the source to "GET AWAY
FROM THE COMPUTER, IT'S SUMMER !!!" and left it the way it was (he had to
be extremely polite to all SVL members for a month). After a time of
lethargy we released SVL 1.1 and 1.2. In order to prevent rumors about
preparing something like SVL 1.5896, we announce that there is not and
never will be any version 1.x (besides 1.1 and 1.2). However, the world
keeps turning round pervertly and so we will keep writing viruses, which
will keep the writers of antiviral software alive (they should at least
support Ahmed Semtex's group in their fight against the Windows threat).
Shouting "LET'S ATTACK IN THE NEW YEAR" [translator's note: it rhymes in
Slovak language, of course :)], we prepare hot news - SVL 2.0 - It will
appear on your computers in the first or the second half of the year.
Actually, it is our personal response to EXPLOSION [translator's note:
Explosion is the first one of the row "Explosion, One_Half and Level_3"].
Finally, we would like to send some hot STEALTH greetings to our favourite
Virus Radar, Vyvojar [note: that's the nick of the guy who wrote the
Explosion series]. Addititonally, we would like to express our unlimited
admiration to the players, who broke the Guiness Record (none of us has
ever played a computer game for more than 40 hours) [note: there was an
attempt to beat the Guiness Record in length of playing the computer games
in Bratislava (the capital of Slovakia) in December '94. The current record
is about 175 hours]. We wish you enough cheap and high-quality software and
If you don't want to have your computers infected, don't buy them!!!
Press Manager of SVL
P.S. The only virus that infected us in 1994 (besides flu, we all caught
it) was OneHalf. We congratulate the author and we offer a meeting
sometime in the future.
Another quality virus from Slovakia is the Lion King virus which is a
polymorphic stealth COM/EXE infector written by an unknown author who
identifies himself as LST.