Froma Joselow was getting ready to bang out a newspaper story when the invisible intruder struck. Joselow, a financial reporter at the Providence Journal-Bulletin, had carefully slipped a disk holding six months' worth of notes and interviews into one of the newsroom computers when the machine's familiar whir was pierced by a sharp, high-pitched beep. Each time she tried to call a file to the screen, the warning DISK ERROR flashed instead. It was as if the contents of her floppy disk had vanished. "I got that sinking feeling," recalls Joselow. "Every writing project of mine was on that disk."
In the Journal-Bulletin's computer center, where Joselow took her troubled floppy, the detective work began immediately. Using a binary editor -- the computer equivalent of a high-powered magnifying glass -- Systems Engineer Peter Scheidler examined the disk's contents line by line. "What I saw wasn't pretty," says Scheidler. "It was garbage, a real mess." Looking for a way to salvage at least part of Joselow's work, he began peering into each of the disk's 360 concentric rings of data.
Suddenly he spotted something that gave him a chill. Buried near Sector 0, the disk's innermost circle, was evidence that the glitch that had swallowed six months of Joselow's professional life was not a glitch at all but a deliberate act of sabotage. There, standing out amid a stream of random letters and numbers, was the name and phone number of a Pakistani computer store and a message that read, in part: WELCOME TO THE DUNGEON . . . CONTACT US FOR VACCINATION.
Joselow had been stricken by a pernicious virus. Not the kind that causes measles, mumps or the Shanghai flu, but a special strain of software virus, a small but deadly program that lurks in the darkest recesses of a computer waiting for an opportunity to spring to life. The computer virus that struck Joselow had been hiding in the memory of the newspaper's machine and had copied itself onto her data disk, scrambling its contents and turning the reporter's words and sentences into electronic confetti.
What was the intruder doing in the newsroom computer? Who had unleashed it and to what purpose? This particular virus was ultimately traced to two brothers who run a computer store in, of all places, Lahore, Pakistan. The brothers later admitted that they had inserted the program into disks they sold to tourists attracted to their store by its cut-rate prices. Their motive: to "punish" computer users for buying and selling bootleg software and thus depriving merchants of potential sales.
The Pakistani virus is only one of a swarm of infectious programs that have descended on U.S. computer users this year. In the past nine months, an estimated 250,000 computers, from the smallest laptop machines to the most powerful workstations, have been hit with similar contagions. Nobody knows how far the rogue programs have spread, and the exact mechanism by which they select their innocent victims -- resting harmlessly in some computers and striking destructively in others -- is still a mystery.