A man in the US has been jailed for 30 months for selling access to thousands of hijacked computers. After taking over more than 72,000 PCs using viruses, Joshua Schichtel of Phoenix, Arizona, would rent out usage of the computers.

Across the world, millions on PCs are enrolled in these sort of networks, known as botnets. Typically, the computers are used to help send out junk email messages, however in this case, Schichtel’s customers would install their own malicious software on the compromised PCs in an effort to aid their own individual cyber-crime efforts.

On top of the 30 month jail term, Schichtel will also be subject to a three-year supervised release programme once he is allowed out of prison. This will tightly control his access to computers and the internet.

The US Department of Justice released a statement saying that Schichtel pleaded guilty to one count of selling access to 72,000 machines that were part of a bigger botnet that he controlled. Remotely attempting to cause damage to computers without authorisation is in breach of the US Computer Fraud and Abuse Act.

Schichtel escaped a conviction in 2004 when he was one of four men accused of using botnets to carry out attacks on websites. The charges had to be dropped on that occasion because the US government failed to file and indictment before a court-imposed deadline.