A History of Computer Viruses

Most computer users are aware that viruses are programs that can create copies of themselves and spread to other computers, but many aren’t aware just how long viruses have been a part of computing. For over fifty years, programmers have been creating self-replicating code for amusement and malice. In the beginning, viruses could only spread by way of removable media like floppy disks, but the rise of the Internet brought the danger of viruses to every computer user..


In 1949, John Von Neumann first suggested that computer programs could spread and self-replicate like organic viruses. However, the first recognized viruses weren’t developed until the late 1960s or 1970s. The two most famous viruses were called “Pervading Animal” and “Christmas Tree”, and they were developed primarily as a way to test the application of biological principles to computing.


Ironically in light of current advertising campaigns, the first true computer virus primarily infected Apple computers. The operating system for early Apple computers was so small it could fit on a floppy disk, and a high school student named Rich Skrenta developed a virus in 1982 called “Elk Cloner” that would attach itself the Apple OS and spread to other users through the floppy disks.

However, it didn’t take long for viruses to start infecting PCs. In 1986, Basit and Amjad Farooq Alvi created the “Brain” virus, which they claimed was actually an attempt to prevent illegal duplication of their software. In 1987, a virus called “Cascade” caused the first real scare by causing infected computers to randomly stop displaying letters on the monitor. Since most people didn’t know about viruses at the time, many user rushed to their monitor supply store for repairs or replacements. The Jerusalem virus, the virus with the most known variants, was first discovered in 1988. The Jerusalem virus is also know as the Friday the 13th virus because every time that date occurs it deletes any programs that are on started that day.


In the 1990s, new anti-virus software like Symantec’s Norton began to appear in the marketplace. However, viruses also continued to grow in complexity. In 1991, the first polymorphic virus, Tequila, was discovered. A polymorphic virus changes its name and file size with each deployment, so they are very hard to detect. The first macro viruses, which spread through the Microsoft Office family of products, also began to spread rapidly in the early 1990s.

The first virus hoax appeared in1994 as the Good Times email. This was an email that warned users not to open any file called “Good Times” because it would erase their whole hard drive. While reported as a hoax many times, the email continues to resurface every few years.

The “Melissa” virus spread rapidly in 1999 and caused an estimated $80 million in damages. Melissa became one of the first viruses that was familiar to many consumers and caused a spike in anti-virus software sales. In 2000, the ILOVEYOU virus infected around ten percent of all computers connected to the Internet and cost over five and a half billion dollars.

Older viruses like Melissa required some sort of user action, such as clicking on a link in an email or opening a Word document. However, some newer viruses like BubbleBoy could be deployed simply when a user opened an email with Internet Explorer.


Unfortunately, virus programmers continue to expand their field of attack. Viruses can now spread through instant messaging, Facebook, MySpace, and even cellphone text messages. Early viruses were more of an attempt to test the limits of technology rather than to cause actual harm, but the rise of electronic banking has led to the development of viruses that are used to steal passwords or other confidential information. Luckily, users have also grown wiser about potential dangers, and the best defense against viruses is still common sense and a wary attitude.