Computer viruses have come a long way since the very first one in early 1970s. Back in those days, computer viruses were basically self-replicating programs which didn’t do a lot of harmful activities (or anything harmful at all).
Most were intended as academic testing purposes, and some were pretty much intended as jokes. The first virus in the wild was Elk Cloner, which essentially cloned itself from floppy disks to spread and upon 50th use, it will show a poem.
Since then, viruses were developed with different purposes. These days when you talk about a computer virus, you think about malicious programs with evil intentions.
For good reasons, too.
Do you know how much destruction computer viruses are causing every year?
Billions.
Yes, that’s in dollars. Millions of computers get infected every year, and billions of dollars are lost.