A 30-year-old Phoenix man was sentenced Thursday to 30 months in prison for using botnets and selling access to them, the US Department of Justice announced.

Joshua Schichtel, allegedly connected to a group of hackers who used denial-of-service attacks to target businesses, was sentenced in US District Court for the District of Columbia. Schichtel was allegedly a member of the so-called DDOS mafia, a group of hackers that attacked websites on behalf of a business owner, but 2004 charges in California were dropped because prosecutors didn't file an indictment by the required deadline.

He pleaded guilty on 17 August 2011, in Washington, DC, to one count of attempting to cause damage to multiple computers without authorisation by the transmission of programs, codes or commands, a violation of the US Computer Fraud and Abuse Act.

Schichtel sold access to botnets, which are networks of computers that have been infected with a malicious computer program that allows unauthorised users to control infected computers, according to court documents. Customers who wanted to infect computers with malware would contact Schichtel and pay him to install malware on the computers that comprised those botnets, the DOJ said.

Schichtel pleaded guilty to causing software to be installed on approximately 72,000 computers on behalf of a customer who paid him US$1,500 for use of the botnet, the DOJ said in a press release.