Geek who hacked computers across globe from mother's Scottish cottage

Computer security expert Matthew Anderson, 33, was head of a gang that targeted hundreds of businesses and homes, including institutions such as the John Radcliffe Hospital and Oxford University, with the spam containing hidden viruses.

The "backdoor" viruses he installed using the spam also allowed him to access the computers and activate webcams - which he did, causing one teenage girl extreme distress, the court heard.

Some of the webcam images found on his hard drive were "potentially compromising" and the court heard the "nosy" computer geek did it for the pure sense of power it gave him.

He also made copies of private documents such as wills, sensitive medical reports relating to children, CVs, password lists and photographs.

Anderson carried out the hacking only because he could and because he enjoyed the feeling of power it gave him, the court heard.

Hugh Davies, prosecuting at Southwark Crown Court in London, said: "The conduct involved the repeated distribution of cleverly disguised e-mails, measured by the millions, bearing sophisticated viruses.

"These computer viruses - alternatively malware - typically avoided virus detection software for about two days following distribution. A variant would then be released and the cycle started again.

"If opened by the recipient, the virus permitted covert access to, and control of, the victim's computer. The damage, as with the location of those responsible, was international."

The Scot was caught after an investigation by Scotland Yard and authorities in Finland into a gang writing computer viruses to order.

The gang, known online as the m00p group, were infecting computers using viruses attached to spam e-mails offering business opportunities, which Anderson himself composed and packed in the e-mails.

They were mostly hidden within a PDF file and the recipient would be encouraged to open it, unaware it would mean their computer would connect remotely to a control server.

He also used the "backdoor" software attached to the virus to access sensitive and private information through remote control and to spy on his unsuspecting victims.Mr Davies said: "There is no particular use apart from him knowing that he had access and others didn't and the power intrinsic to the state of affairs."

Chat with other hackers found on his computer show Anderson joking: "Had some chick on webcam changed her screen about a bit n she started to cry lol."

He admitted to fellow hacker CraDle it had been unauthorised access to the webcam. Using the alias warpigs, he wrote: "Took pics :D lol of her crying lol."

Mr Davies added that Anderson was at the "cutting edge" of international virus e-mails and part of the "top-end international hacking community".

Anderson, from Drummuir, Aberdeenshire, used the profile names "aobuluz", "warpigs", "zuluboa" and "ZeePuig" and operated behind the front of Optom Security, which offered security software online.

Sometimes, the hacked computers cost thousands of pounds to repair. Mr Davies said: "Leaving aside basic considerations relating to the systematic and gross breaches of privacy, the particular enterprise inevitably caused such practical inconvenience and expense to an unquantifiable number of victims."

One e-mail infected 743 computers in only 30 minutes.

Anderson, who plotted with other hackers to orchestrate the massive spam, even joked with a co-conspirator known as "Alm" that they should include the Queen's phone number in the spam "for mischief".

Anderson, a father of five, pleaded guilty to causing unauthorised modifications to the contents on computers under the Computer Misuse Act between September 2005 and June 2006. He had been on bail for orchestrating a "denial of service" attack on two organisations he disagreed with - the BNP and the Countryside Alliance - when he committed the latest offences.

Simon Ward, defending, said: "There is no criminal motive behind what the defendant did. This is all about a feeling of power that comes from the knowledge that you have control of something and other people don't realise you have the control of it.

"There is no evidence of blackmail … no evidence of identity theft, no evidence of any of this material being passed to other people. He was behaving as a foolish young man who should have known better."

Judge Geoffrey Rivlin, QC, will pass sentence today.

The case follows that of another Scot, Gary McKinnon, 44, who is facing decades in a US jail for crimes allegedly committed from his north London home.

McKinnon, who suffers from Asperger's syndrome, a form of autism, is fighting attempts to extradite him to the US for allegedly hacking into Pentagon computers searching for the existence of alien beings.