Hacker toolkits that used to be available only on hidden forums are now for sale on eBay, according to security vendor Tier-3.

The development is further evidence of the burgeoning and complex trade network that supports e-crime on the internet, said Geoff Sweeney, chief technology officer at Tier-3.

'High level hacking tools, including surreptitious trojan loaders and Web site hacking utilities, are being put into the hands of almost any internet user,' he said.

The kits are often sold as ethical hacker training courses, but can easily be used for malicious purposes.

“We are satisfied that the presence of such an item on the US site is not commonplace, as although we have 100m listings live on the site globally at any one time, we are very effective at removing prohibiting items, often before the listing ends and any sale is completed," said eBay in a statement.