In 1971, Bob Thomas, an engineer working for Bolt, Beranek and Newman, the Boston company that had the contract to build the Arpanet, the precursor of the Internet, released a virus called the “creeper” on to the network. It was an experimental, self-replicating program that infected DEC PDP-10 minicomputers. It did no actual harm and merely displayed a cheeky message: “I’m the creeper, catch me if you can!” Someone else wrote a program to detect and delete it, called — inevitably — the “reaper.”
Although nobody could have known it 40 years ago, it was the start of something big, something that would one day threaten to undermine, if not overwhelm, the networked world. For as we became more and more dependent on information and communications technology, we were also subjected to a plague of what came to be called “malware.”
It’s an ugly term, as befits something that covers a multitude of sins, all involving computer code designed with destructive or malevolent intent. It includes not only viruses, which are programs that replicate by copying themselves into other programs, but also worms (self-replicating programs that use a network to send copies of themselves to other machines on the network, with or without human assistance) and Trojans (similar to viruses but instead of replicating they infiltrate a computer and perform some illicit activity, possibly under remote control). Malware also refers to other evils: the junk mail we call spam; “phishing,” or trying to hoodwink Internet users into revealing bank account passwords etc; page-jacking, which makes it difficult or impossible for a victim to get rid of a Web page; and other scams.
The malware plague has gone through several phases. It began in a harmless and experimental way with the creeper and a worm released on to the Internet in 1988 by Robert Morris, a student from New York State’s Cornell University. Morris wanted to find out how many computers were connected to the Internet so he wrote a small program that would install itself on every machine it found and send back a “present and correct” message.
But there was a flaw in his code that meant the worm replicated. On Nov. 2, 1988, network administrators realized something was up because their machines — and the network itself — had slowed to a crawl. In the end, the culprit was identified and carpeted, though it doesn’t seem to have done him any lasting harm: Morris is now a professor at the Massachusetts Institute of Technology.
Malware began on the Internet, but its next phase involved the stand-alone machines we now call personal computers. In 1982, a Pennsylvanian teenager named Rich Skrenta created the “elk cloner” virus that infected the Apple II, then the most popular personal computer in upmarket US households. Skrenta’s virus covertly altered the floppy disk needed to boot up the computer, displaying some doggerel on the screen on start up. It was annoying but harmless.
Early PC malware tended to be like that — irritating but not terribly destructive. And malware spread slowly, because most of these PCs were not networked; infections spread by “sneakernet” — i.e., users sharing floppy disks. The real trouble began when domestic Internet use exploded in 1993. From then on, an infected PC was a potential menace not just to its owner, but to other machines with which it communicated.