Back in the days a lot of thought and ingenuity was put into making these viruses. For instance, the Friday 13th [1][2][3] virus:<p>* was only 419 bytes long<p>* infected both .COM and .EXE, increasing the size of the former by only 1813 bytes<p>* on infection, became memory resident (using only 2kb of memory)<p>* hooked itself into interrupt processing and other low level DOS services to, for instance, suppress the printing of console messages in failure cases (like trying to to infect a file on a read-only floppy disk)<p>* activated itself every friday 13th and deleted programs used that day<p>It still managed to spread itself worldwide (mostly via floppy disk sharing as the world wide web didn't exist yet) and went mainstream enough for the broadcast news to advise people not to turn on their computers on that date or to push the date one day ahead.<p>All that in 419 bytes, about a third of the size of this post.<p>[1] <a href="https://en.wikipedia.org/wiki/Jerusalem_%28computer_virus%29" rel="nofollow">https://en.wikipedia.org/wiki/Jerusalem_%28computer_virus%29</a><p>[2] <a href="https://www.f-secure.com/v-descs/jerusale.shtml" rel="nofollow">https://www.f-secure.com/v-descs/jerusale.shtml</a><p>[3] <a href="http://www.pandasecurity.com/mediacenter/malware/famous-virus-history-friday-13th/" rel="nofollow">http://www.pandasecurity.com/mediacenter/malware/famous-viru...</a>
I wrote an AV Scanner (for the lulz) in the early 1990's and ended working at Symantec for my sins. Some of the programs were seriously well coded with self-hamming code, polymorphism, multi-partite capabilities, etc. Some of my favourites were the 'Eddie' series - written by a Bulgarian guy with a liking for Iron Maiden. :)
I remember this ezine 40Hex used to have virus assembly in it, which to my 12 year old self was pretty much the coolest thing I could imagine, until I compiled and accidentally ran it and destroyed my parents Windows 98 installation.
The good old days... when viruses merely displayed a funny message or erased your hard disk, but didn't turn your computer into part of a botnet controlled by organized crime.
Viruses were so much better before
<a href="https://archive.org/details/malware_ZOHRA.COM" rel="nofollow">https://archive.org/details/malware_ZOHRA.COM</a>
I remember back in the 90s, demonstration of the viruses (with all animations, music, etc.) was one of the coolest features of popular Polish antivirus mks_vir.
Malware back then was usually pranks. Today it's mostly run by organized crime. Money changes everything.<p>I wrote DOS viruses when I was fifteen or sixteen. Most of them didn't do anything or did silly little pranks, but it's how I learned X86 ASM.
I remember actually getting infected with one of these when I was a teenager. From what I recall, it was mostly harmless.<p>Me and some friends pooled together and bought a couple of CD-ROM's full of warez from some guy we found online and one of the games or applications was infected. Looking back, I'm actually pretty more all of them weren't infected!
In the early 90s, I created a stealth benign virus in just 127 bytes. Good old times!<p>Back then, one of the most amazing virus was Whale [0]!<p>[0]: <a href="http://www.mycal.net/Group42/virus/40hex/40hex22.htm" rel="nofollow">http://www.mycal.net/Group42/virus/40hex/40hex22.htm</a>
Imagine being a virus writer crafting a virus so complicated that it would only work in a future not written different kind of OS or virtual machine, and work in differing operating systems, and identify and poke for weaknesses by itself.<p>Perhaps it would just be a Science Fiction plot device!
What a great compilation! I would love to know what harmful effects they had though. It is quite a difference if the virus is erasing your HDD while it is slowly printing the nice message or not...
I used to collect these too! Thanks for posting!<p>I'll have to look to see if there are any familiar boot sector viruses - the kind that propagated via floppies. Those made the rounds at work.<p>I enjoyed disassembling them and seeing how they work. It was an education that kids miss out on today.<p>Come to think of it, back when I was teaching a Perl class one of my first assignments was to create a "virus" that found Perl scripts and copied itself into them. Good times.
This is awesome. But, I was really hoping for Stoned. It was the first virus I got.<p><a href="https://en.wikipedia.org/wiki/Stoned_%28computer_virus%29" rel="nofollow">https://en.wikipedia.org/wiki/Stoned_%28computer_virus%29</a>
If you're interested in this stuff, there#s also an awesome archive at VX Heaven [1], which not only includes malware sources but also a lot of documentation, simulators etc.<p>[1] <a href="http://vxheaven.org/" rel="nofollow">http://vxheaven.org/</a>
An F-PROT v2 with its virus descriptions running in em-dosbox would be an appropriate addition to those viruses: <a href="http://patraulea.com/fprot/" rel="nofollow">http://patraulea.com/fprot/</a>