The web designer and part-time DJ, is a young, skilled techie, with typically laddish interests in music, alcohol, partying and women.
Vallor admitted to releasing the Redesi, Admirer, and Gokar worms, after a joint investigation by the FBI and Scotland Yard's computer crime unit traced him to a housing estate in Llandudno.
The Gokar virus, a sophisticated mass-e-mailer, infected an estimated 27,000 computers in 42 countries, forcing companies to clean and reconfigure their systems.
Vallor, now penitent about his activities, has chronicled his story on his web site, The Devil Within. His online dairy reveals how he tried to cope with the fear of jail by turning to drink and drugs.
"Needless to say I am feeling very nervous and apprehensive about Tuesday but sadly there is not much I can do about it now," he told Computer Weekly shortly before he was sentenced.
Graham Cluley, chief technologist at anti-virus company Sophos, said Vallor had all the traits of a typical virus writer and was largely motivated by showing off to his mates.
"His online diary is a bit sad. Some of it resorts to sixth-form angst rather than the happening social life he thinks he has," he said.
Hacker Mitnick tells it straight >>