To Jim, the concept of viral blackmail sounded unlikely. As far as he knew, no one had ever made a penny out of writing virUses. It was said that if there was any money in writing bugs, Bulgaria would be one of the richest countries in Europe; but instead it remained one of the poorest.
At 5:30 that afternoon, December 12,1989, the package from PC Business World arrived. As promised, it contained a diskette, of the sort sent out to the magazine's readers; it also contained a copy of a blue instruction leaflet that had accompanied the diskette.
Jim examined the leaflet closely. "Read this license agreement carefully [and] if you do not agree with the terms and conditions . . . do not use the software," it began. It then stated that the program on the diskette was leased to operators for either 365 uses at a price of $189, or the lifetime of their hard disk at a price of $389. "PC Cyborg Corporation," it continued, "also reserves the right [sic] to use program mechanisms to ensure termination of the use of the program [which] will adversely affect other program applications."
So far, Jim thought, it read much like a normal software licensing agreement, except for the warning that the program might "adversely effect other program applications."
But farther down in the small print on the leaflet was a paragraph that made him sit up. "You are advised of the most serious consequences of your failure to abide by the terms of this agreement: your conscience may haunt you for the rest of your life . . . and your computer will stop functioning normally [authors' italics]."
This, Jim thought, was carrying the concept of a licensing agreement too far. Licensing software was a perfectly acceptable business practice, as was making threats that unauthorized users of their products would be prosecuted for "copyright infringement." They never threatened to punish unauthorized users by damaging their computers.
Even more unusual, the diskette had been sent out like junk mail, unrequested, to computer users around Great Britain, inviting them to run it on their machines. Whoever had distributed the diskettes had obviously purchased PC Business World's mailing list, which the magazine routinely rented out in the form of addressed labels. The magazine had seeded its list with names and addresses of its own staff, an ordinary practice that allows the renter to check that its clients aren't using the list more often than agreed. These seeded addresses had alerted the magazine to the existence of the diskette. If the publication had received copies from its seeded addresses, so had some seven thousand others on the mailing list. And Jim knew that many of these would have loaded the program without reading the blue leaflet--which was, in any case, printed in type so small that it was almost unreadable. Anyone who had already run the diskette, Jim thought, could well be sitting on a time bomb.
Later that evening an increasingly anxious Mark Hamilton phoned again: "We're now getting reports that this disk has been found in Belgium, Paris, Germany, Switzerland, Scandinavia, and Italy. Can you do anything with it?"
In fact, Jim was already working on an antidote. He had loaded the diskette on an isolated test computer in his upstairs office and had discovered that it contained two very large executable files: an "Install" program and an "AIDS" program. Jim had previously attempted to run the AIDS file on its own, but after a few seconds it aborted, displaying the message: "You must run the Install program before you can use the AIDS program."
He followed the instructions, warily loading up Install. It beeped into life, the light on the hard disk flickering off and on. When the installation was finished, Jim looked at the hard disk, using software designed to see all of the files listed in the computer's various directories. The software also allowed him to see any "hidden" files, those generally concealed from casual inspection to prevent them being deleted accidentally. There are always two hidden operating system files on a hard disk; but now, after running the Install program, there was suddenly a whole series of them, none of them named.
