Happy 20th virii!

Today is November 13, 2003. On November 10,1983 Fred Cohen presented a paper at a security seminar that would wreck havoc for decades.

He didn't write a virus or show people how to write one, he just proved that it could be done. Before him it was no more than a mathematical possibility written about by computer scientists like John Von Nuemann.

While all he did was define a virus as "a program that can infect other programs by modifying themselves to include ... version of itself." It didn't take long before people were writing virus-like games that were fascinating to computer scientists but they were so benign that one was published in a major magazine. On May of 1984, Scientific America included a copy of "core wars" which put two programs head-to-head in a cage fight. They would steal each others memory until one of them was destroyed.

I understand that about this time it was common in universities for students to compete with each other on who could write the smallest self-reproducing program (a virus in today's speak) in languages like Fortran or Cobol. It was easy to write a small program in Assembly, but where is the challenge in that?

Until the last decade, virus' were primarily harmless jokes. But malicious self-reproducing programs have been around since 1986.

The "Pakistani Brain" and "Friday the 13th" were a couple of the first malicious viruses. "Brain" infected a vital part of the disk called the "boot sector". "Friday the 13th" would delete files on a regular basis. Guess which day the evil work was done.

If you want to learn more about viruses there are a couple of books to look at. If you're mathematically inclined, you might want to try Dr. Von Nuemann's "Theory and Organization of Complicates Automata". To see Dr. Cohen's work, read the book he published in 1986, "computer viruses" through ASP press. If you want even more details then get "The Giant Black Book of computer viruses" by Dr. Mark Ludwig (published by American Eagle Press 1995). Just be sure to turn your AntiVirus program off before you down-load a file from the CD. If your AV has no problems with those files then your AV has a problem.

Back to 20 years ago. Dr Cohen really is against viruses All he did was prove that they could exist.