The "TK" worm was released onto the internet early this year and, according to the BBC, used chat channels to infect computers with a malicious Trojan horse – a program that installs itself onto a computer without the owner's knowledge, usually by deceiving the owner about what he or she is getting when opening an e-mail attachment or downloading a file from the internet.
Once installed, the Trojan horse can carry out malicious acts such as destroying data, scanning other machines or even downloading illegal material from the internet. In this instance the self-replicating worm caused damage to computers estimated at £5.5 million.
An international investigation ensued, involving members of the UK's National Hi-Tech Crime Unit (NHTCU) and the Computer and Technology Crime Hi-Tech Response Team (CATCH), based in Southern California.
The two suspects, Jordan Bradley, 20, of Darlington, and Andrew Harvey, 22, from Belmont, County Durham, were initially arrested in February this year, under suspicion of being members of the international hacking group known as "Thr34t-Krew" which is behind the "TK" worm. A US man was arrested at the same time.
Bradley and Harvey have now been formally charged and are due to appear before Consett magistrates on 18th September.
Formal charges have also been brought against a Romanian man this week, in connection with the release of a version of the Blaster worm that infected computers in late August. According to Reuters, 24 year old Dan Dumitru Coibanu has been charged under a new Romanian cybercrime law, and will face a sentence of between three and fifteen years if convicted.