NOTE: A version of this essay originally appeared at The Register in 2015.

I was 17 years old, I had nothing to do, and I wanted to teach myself PC programming. So I decided to write a computer virus.

Don’t worry. The two viruses that I ended up writing – Leprosy and Leprosy-B – were designed to infect MS-DOS computers. They knew nothing about the internet, Windows, stealing people’s data, or anything remotely sophisticated, because neither did I at the time. And today, both viruses are as dead as smallpox.

My reasons for wanting to write software that trashed other people’s PCs weren’t that complex. For starters, as I said, I was 17. Petty vandalism kind of comes with the territory. Maybe sticking to computers was a better idea.

I was already a bit of a hacker, having taught myself Basic, Pascal, assembly language, and Forth on an Apple ][ years earlier. But the PC worked differently, and I wanted to figure it out.

Perhaps the main reason, though, was that I was a bit full of myself and I wanted to do something about the arrogance that I felt existed in the underground computer scene at the time. I just wanted to prove to the scenesters that even an idiot who didn’t really know how to program could write a virus. » More... » →