A Brazilian man has been charged for trying to rent out a botnet that would be used to send spam, U.S. authorities said Thursday.

Leni de Abreu Neto, 35, of Taubate, Brazil, was charged with one count of conspiracy to cause damage to computers worldwide after being indicted by a federal grand jury in the U.S. District Court for the Eastern District of Louisiana.

Neto was arrested in the Netherlands on July 29 by the Dutch High-Tech Crime Unit, with assistance from the U.S. Federal Bureau of Investigation. The U.S. is seeking his extradition.

Neto was arrested along with a 19-year-old Dutch man, Nordin Nasiri, and Nasiri's 16-year-old brother. Nordin Nasiri, of Sneek, Netherlands, had built a network of some 100,000 hacked computers.

Such networks, known as botnets, are valuable for cybercriminals, who can route their hacking through the compromised computers, making it difficult for investigators to follow. The controlled PCs are used to send spam or perform other malicious actions such as a denial-of-service attack, which can cripple a Web site.

Between May and June, Neto agreed with Nasiri to act as a mediator to rent out the botnet to another party for €25,000 ($37,290), according to the indictment. Neto expected the third party to use the botnet to send spam.

The botnet, called "Shadow" by Nasiri, was spread entirely through social engineering. The malicious code was distributed on Microsoft's Windows Live Messenger instant messaging network.

Once on a PC, the malicious code would send instant messages to people on the victim's contact list. The messages contained a link to what appeared to be a harmless file but could actually gave Nasiri control over the PC.

If convicted Neto faces up to five years in prison plus three years of probation. He could also be fined as much as $250,000 or more depending on the losses from victims or his own profits from the scheme.

Nasiri will be prosecuted by Dutch authorities.

The IDG News Service is a Network World affiliate.