WELLINGTON, April 1: A New Zealand teenager was convicted on Tuesday for his central role in a global cyber-crime ring which infected at least 1.3 million computers worldwide and caused millions of dollars in losses.

Owen Thor Walker, 18, allegedly led a group of international hackers who used his programmes to access personal data, send viruses around the world and commit other crimes, causing losses of $20 million, police say.

The thin, long-haired teenager pleaded guilty to six computer crimes in a court in Thames, near his home south of Auckland, and is due to reappear on May 28 for sentencing.

Walker showed no emotion and did not speak during the short hearing after pleading guilty through his lawyer to the charges, which carry a maximum sentence of up to seven years in prison.

The teen, who taught himself programming and used the online name “Akill”, began committing the alleged crimes early last year and continued until late 2007, a prosecution summary said.

Walker, who suffers from Asperger’s syndrome, a mild form of autism, designed an encrypted virus that was undetectable by anti-virus software and made nearly $40,000 (US$31,450) from selling it, police said.

He started experimenting with virus programmes and created his own code, continually developing and redesigning it.

International investigators considered Walker’s programming to be “amongst the most advanced” they had encountered, the prosecution summary said.

Also working online as “Snow Whyte” and “Snow Walker,” Walker controlled his network using computer servers outside New Zealand, mainly in Malaysia, either leasing server space or accessing servers illegally.

Prosecutors said the exact number of computers in which his malicious or bot code was installed may never be known.

Walker’s software allowed access to user names and passwords, as well as credit card details, and was used by other criminals to commit crimes.

New Zealand police cooperated with the US Federal Bureau of Investigation as well as Dutch authorities to uncover the network.

The investigation started after an attack involving 50,000 computers crashed the server at the University of Pennsylvania in 2006.

Walker was living with his parents when he committed the crimes, but they believed he was doing legal computer programming work, a police statement said.

The charges included creating software which allowed unauthorised access to computer systems, installing malicious software onto networks, using unauthorised computer access for financial gain and interfering with computer systems.—AFP