Researchers have uncovered a fully-functional marketplace for the building and selling of botnets.

Security firm Finjan said that the site allows criminals to obtain everything from malware and data, to networks of infected PCs.

Yuval Ben-Itzhak, chief technology officer at Finjan, described the new site an "eBay for stolen data".

"It is basically a hacker-to-hacker platform to provide everything you want, " he said. "You do not need to go elsewhere. You get everything you need to do the business."

The sale of malware and botnets is hardly new, but the new site shows the growing sophistication of such markets, and the ease with which cyber criminals can enter the botnet field.

Finjan also said that much of the malware being offered uses encryption and obfuscation to help evade security software.

Even the site itself is difficult to track. Ben-Itzhak explained that the people behind the site have used techniques such as blacklisting and redirecting through proxy servers in order to keep security experts and law enforcement groups away.

The level of sophistication and amount of data being brokered points to a large and highly organised operation, according to Ben-Itzhak.

"The investment in this platform and the number of participants indicates that there is a big business here," he said.