A New Zealand teenage whizz-kid who admitted developing software that infected a million computers around the world has been hired by telecommunications company TelstraClear to advise companies how to avoid hackers.

Owen Walker, 19, who was tracked down by the United States Federal Bureau of Investigation, is advising on "botnets" - networks of computers infected by malicious software - TelstraClear spokesman Chris Mirams told Radio New Zealand on Wednesday.

Walker admitted when he appeared in court in July to being part of what the FBI called "an elite international botnet coding group" that caused chaos around the world, including shutting down the entire network of 50,000 computers at the University of Pennsylvania.

A judge discharged Walker, who was at high school at the time, without penalty, saying he had not acted with criminal intent and a conviction could jeopardize his potentially outstanding future.

Walker had turned down numerous job offers from companies around the world and said he wanted to be the next Bill Gates, the New Zealand Press Association reported.