The recently found bug in the internet's Domain Name System (DNS) is more serious than originally thought according to internet security expert Dan Kaminsky. Speaking at the Black Hat conference in Las Vegas, Mr Kaminsky outlined fifteen different ways that hackers could hijack the DNS, redirecting users to fake web pages.

The DNS is the internet's address book. It converts user friendly domain names, such as excite.co.uk, into binary, so they can be read by computers. While DNS hacking is not new, Mr Kaminsky's research has revealed the potential weaknesses in the system and how they can be exploited.

Last month Microsoft, Cisco, and Sun Microsystems all released patches to deal with the problem. But Mr Kaminsky told the BBC that since publishing his findings, 75% of Fortune 500 companies have taken appropriate action, while 15% have done nothing at all.