Security researchers have discovered a new web-based attack tool which exploits up to 14 browser vulnerabilities and installs malware on the user's system.

Symantec researcher Liam O'Murchu said that 'Tornado' is commonly installed on a server by a single 'administrator', who then offers accounts on the server to other attackers.

The attackers then inject code into other web pages to redirect users to the Tornado server, where the exploit and malware installation is conducted.

"Perhaps this is why the code for this pack has stayed private for so long," said O'Murchu.

"Using this model, the creators of the pack can sell it to a few trusted customers at a higher price, rather than selling it to many untrustworthy customers and risking the code being released in the underground."

Tornado also offers attackers a full set of traffic statistics and options for selecting which exploits can be conducted.

The malware features an option to redirect repeat visitors to a phoney 'account suspended' page.

This helps the tool to evade security researchers who will make repeated visits to infected pages in order to study the exploits and malware in use.

Programs such as Neosploit and MPack offer similar capabilities to set up servers that can conduct multiple exploits against users.