A man who admitted infecting thousands of computers with viruses has claimed he did not think his work would spread across the world.

Simon Vallor, 22, created the viruses at his home in Llandudno, north Wales, and released them on to the internet.

I made a mistake and at the end of the day I've got to pay a price for that mistake Simon Vallor

Vallor admitted three counts of releasing a computer virus, contrary to section three of the Computer Misuse Act 1990 on or before 14 February last year.

He was jailed for two years at Southwark Crown Court on Tuesday.

The judge also ordered that Vallor's computers be confiscated and the hard drives destroyed.

The "mass-mailer" viruses were sent as e-mails that were automatically sent to everyone on the computer's address book.

Vallor is thought to have seized-up 27,000 computers and caused mayhem in 42 countries with bugs dubbed 'Gokar', 'Admirer' and 'Redesi'.

Widespread

One 'worm' was, at the time, the third most widespread in the world.

Speaking to BBC Wales as he awaited sentence, DJ and web designer Vallor claimed he did not think the viruses would spread.

He said: "You hear about worms all the time. There are 10, 15, that come out a day and you never actually hear of them because they don't spread.

"I just thought that was that, I'd never hear of it again.

"But obviously it didn't happen like that."

Vallor wants to continue working in computers

Vallor added that he was interested in computers as a teenager, but began to spend more time learning about programming after the death of his mother.

He said: "I started spending 20 hours a day on the computer.

"That was what my life revolved around - it was out of bed and onto the computer.

"(It was) escapism, to get away from everything that was happening around me.

"No-one knew me online - it was to get away from everyday life."

Vallor claimed he stumbled upon how to create viruses while learning about computer programming.

'Experiment'

He added: "To start with it was just a programme experiment. I was just exploring the function.

"I didn't have a clue it (the virus) was going to spread at all."

Vallor claimed that his viruses were not destructive and that they merely spread from computer to computer.

He said: "It wouldn't damage your computer. If you were infected by it, you wouldn't notice anything at all.

"It wouldn't delete files or corrupt any data.

"It would spread, but it didn't have a destructive payload.

"The amount of mail it was sending could flood e-mail servers (but) there was no destruction of data."

But Vallor admitted that he had made a mistake in creating the viruses and sending them out.

'Mistake'

He said: "I made a mistake and at the end of the day I've got to pay a price for that mistake."

He added that he wanted to work in computers in future.

"Graphics or web design - computers are what I do," he said.

"I've learned from my mistakes and hopefully people will forgive me."

'Steps'

But the court heard that Vallor's viruses had caused damage to computers.

Graham Cluley, a senior technology consultant at Sophos Anti Virus - a company which protects businesses from computer viruses - told BBC Wales that computer users needed to take steps to protect themselves against viruses of the kind Vallor was creating.

He added: "What we really recommend to people is to use anti-virus software, but crucially to keep it up to date because there are new viruses coming out all the time.

"The other good rule is just be sensible.

"If you receive an e-mail and it looks too good to be true or it's offering something a little bit salacious then think before you click on it."