Virus writers are especially hostile toward Microsoft, the perennial whipping boy of the geek world. From their (somewhat self-serving) point of view, Microsoft is to blame for the worm epidemic, because the company frequently leaves flaws in its products that allow malware to spread. Microsoft markets its products to less expert computer users, cultivating precisely the sort of gullible victims who click on disguised virus attachments. But it is Microsoft's success that really makes it such an attractive target: since more than 90 percent of desktop computers run Windows, worm writers target Microsoft in order to hit the largest possible number of victims. (By relying so exclusively on Microsoft products, virus authors say, we have created a digital monoculture, a dangerous thinning of the Internet's gene pool.

Microsoft officials disagree that their programs are poor quality, of course. And it is also possible that their products are targeted because it has become cool to do so. "There's sort of a natural tendency to go after the biggest dog," says Phil Reitinger, senior security strategist for Microsoft. Reitinger says that the company is working to make its products more secure. But Microsoft is now so angry that it has launched a counterattack. Last fall, Microsoft set up a $5 million fund to pay for information leading to the capture of writers who target Windows machines. So far, the company has announced $250,000 bounties for the creators of Blaster, Sobig.F and Mydoom.B.

The motivations of the top virus writers can often seem paradoxical. They spend hours dreaming up new strategies to infect computers, then hours more bringing them to reality. Yet when they're done, most of them say they have little interest in turning their creations free. (In fact, 99 percent of all malware never successfully spreads in the wild, either because it expressly wasn't designed to do so or because the author was inept and misprogrammed his virus.) Though PhiletOast3r is proud of his keylogger, he said he does not intend to release it into the wild. His reason is partly one of self-protection; he wouldn't want the police to trace it back to him. But he also said he does not ethically believe in damaging someone else's computer.

So why write a worm, if you're not going to spread it?

For the sheer intellectual challenge, PhiletOast3r replied, the fun of producing something "really cool." For the top worm writers, the goal is to make something that's brand-new, never seen before. Replicating an existing virus is "lame," the worst of all possible insults. A truly innovative worm, PhiletOast3r said, "is like art." To allow his malware to travel swiftly online, the virus writer must keep its code short and efficient, like a poet elegantly packing as much creativity as possible into the tight format of a sonnet. "One condition of art," he noted, "is doing good things with less."

When he gets stuck on a particularly thorny problem, Phile-tOast3r will sometimes call for help from other members of the Ready Rangers Liberation Front (which includes Mario). Another friend in another country, whom PhiletOast3r has never actually met, is helping him complete his keylogger by writing a few crucial bits of code that will hide the tool from its victim's view. When they're done, they'll publish their invention in their group's zine, a semiannual anthology of the members' best work.

The virus scene is oddly gentlemanly, almost like the amateur scientist societies of Victorian Britain, where colleagues presented papers in an attempt to win that most elusive of social currencies: street cred. In fact, I didn't meet anyone who gloated about his own talent until I met Benny. He is a member of 29A, a superelite cadre within the virus underground, a handful of coders around the world whose malware is so innovative that even antivirus experts grudgingly admit they're impressed. Based in the Czech Republic, Benny, clean-cut and wide-eyed, has been writing viruses for five years, making him a veteran in the field at age twenty-one. "The main thing that I'm most proud of, and that no one else can say, is that I always come up with a new idea," he said, ushering me into a bedroom so neat that it looked as if he'd stacked his magazines using a ruler and level.

"Each worm shows something different, something new that hadn't been done before by anyone."

Benny-that's his handle, not his real name-is most famous for having written a virus that infected Windows 2000 two weeks before Windows 2000 was released. He'd met a Microsoft employee months earlier who boasted that the new operating system would be "more secure than ever"; Benny wrote (but says he didn't release) the virus specifically to humiliate the company. "Microsoft," he said with a laugh, "wasn't enthusiastic." He also wrote Leviathan, the first virus to use "multithreading," a technique that makes the computer execute several commands at once, like a juggler handling multiple balls. It greatly speeds up the pace at which viruses can spread. Benny published that invention in his group's zine, and now many of the most virulent bugs have adopted the technique, including last summers infamous Sobig.F

For a virus author, a successful worm brings the sort of fame that a particularly daring piece of graffiti used to produce: the author's name, automatically replicating itself in cyberspace. When antivirus companies post on their Web sites a new "alert" warning of a fresh menace, the thrill for the author is like getting a great book review: something to crow about and e-mail around to your friends. Writing malware, as one author e-mailed me, is like creating artificial life. A virus, he wrote, is "a humble little creature with only the intention to avoid extinction and survive."

Quite apart from the intellectual fun of programming, though, the virus scene is attractive partly because it's very social. When PhiletOast3r drops by a virus-writers chat channel late at night after work, the conversation is as likely to be about music, politics, or girls as the latest in worm technology. "They're not talking about viruses-they're talking about relationships or ordering pizza," says Sarah Gordon, a senior research fellow at Symantec, an antivirus company, who is one of the only researchers in the world who has interviewed hundreds of virus writers about their motivations. Very occasionally, malware authors even meet up face-to-face for a party; PhiletOast3r once took a road trip for a beer-addled weekend of coding, and when I visited Mario, we met up with another Austrian virus writer and discussed code for hours at a bar.

The virus community attracts a lot of smart but alienated young men, libertarian types who are often flummoxed by the social nuances of life. While the virus scene isn't dominated by those characters, it certainly has its share-and they are often the ones with a genuine chip on their shoulder.

"I am a social reject," admitted Vorgon (as he called himself), a virus writer in Toronto with whom I exchanged messages one night in an online chat channel. He studied computer science in college but couldn't find a computer job after sending out four hundred resumes. With "no friends, not much family," and no girlfriend for years, he became depressed. He attempted suicide, he said, by walking out one frigid winter night into a nearby forest for five hours with no jacket on. But then he got into the virus-writing scene and found a community. "I met a lot of cool people who were interested in what I did," he wrote. "They made me feel good again." He called his first virus FirstBorn to celebrate his new identity. Later, he saw that one of his worms had been written up as an alert on an antivirus site, and it thrilled him. "Kinda like when I got my first girlfriend," he wrote. "I was god for a couple days." He began work on another worm, trying to recapture the feeling. "I spent three months working on it just so I could have those couple of days of godliness."