Up to 40 per cent of new Facebook profiles could be fictitious registrations created by spammers and malware writers to infect end users, security firm Cloudmark has warned.

Neil Cook, European head of technology services at Cloudmark, told vnunet.com that research carried out by the firm revealed that between 20 and 40 per cent of new profiles on the popular social networking site could be bogus.

Cook explained that, once set up with a portfolio of fake profiles, virus writers encourage users to click on links to malicious sites by including them on postings on other users' walls or blogs.

Another tactic is to try and get users to visit their profile pages through friend requests or personal messages. The profile page then redirects visitors to a malware site.

"Social networks are very collaborative so it's great for spammers and virus writers to attack," said Cook. "As soon as social networking took off, so did the attacks."

Cook also predicted that SMS spam would eventually seep into the UK market, spreading from China and other Asian countries.