Walker, 19, had been facing possible jail time for running a massive botnet that infected as many as 1 million computers, but in July he caught a big break. That's when a New Zealand judge ordered him to pay a fine after he pleaded guilty to hacking charges.
Last year, Walker was busted in a joint New Zealand/U.S. Federal Bureau of Investigation operation called , which landed one of his associates, 22-year-old University of Pennsylvania student Ryan Goldstein, in prison.
Now working for a small New Zealand software company, Walker has become a minor celebrity in his home country. He was this week on New Zealand's TV3 60 Minutes program, which described him as "the teenage boy with a brain that's one in a billion."
Walker, who was known online as Akill, and in his hometown of Whitianga as Snow, comes across as a typical geek in the report. An early reader who loved books, he was diagnosed with Asperger syndrome as a child. He was teased so mercilessly at school that his mother eventually decided to home-school him. By 15, he was drawn to computer programming and was often spending eight to 10 hours on the computer after school.
He eventually branched into malware because he found it "really interesting," and he "didn't have a lot else to do at the time," he says in the interview.
Police say he started his criminal activities at the tender age of 16.
"I knew it was illegal," he says. "I just didn't think it was that bad. Like, just a bit of fun, as you do when you're a teenager."
Walker estimates that he made $40,000 (US$21,500) from his illegal operation, most of which was spent in true geek fashion. "I spent it on toys like a new computer, X-Box, games, buying pizzas for friends," he says.
His parents, also interviewed in the TV3 piece, knew they had a nerdy kid. But on the day of Walker's bust they didn't think they were raising a criminal. His stepfather, Bill Whyte, remembers the arrest: "I initially thought porn," he says, thinking his son was "too straight" for cybercrime.
Walker may have received a light sentence, but even New Zealand police didn't think he should go to jail. "The worst thing that society could have done was put him in jail, where his mind would have been corrupted," Maarten Kleintjes, head of e-crime with New Zealand Police, says in the interview.
Since the arrest, Walker has had several job offers, he says. But now that his illegal hacking days are behind him, he'd like to work for himself.
"Ultimately, I'd like to start my own company," he tells TV3. "Maybe [become] the next Bill Gates."