The vast majority of people are blind to spyware, adware and other unwanted software according to a survey sponsored by security software firm, McAfee.

Alarmingly, in a survey of more than 14,000 Internet users, 97 per cent of them were found to be 'one click away' from infecting their PCs with unwanted or malicious software.

Only three per cent of those that took the Siteadvisor spyware quiz received perfect scores. The survey challenged web surfers to test their ability to detect which sites in a number of popular categories were free of adware or spyware.

The type of sites chosen represent the most notorious sources of unwanted software: screensavers, smileys, free games, song lyrics, and file-sharing applications.

The ones in the survey were chosen from three million sites already tested and given a safety rating.

'We know it's not easy to judge a site's safety just by looking at it, but that's the point: bad sites are often very good at providing an aura of safety,' said Chris Dixon, head of McAfee's Siteadvisor development.

'No matter how knowledgeable or perceptive you are, you can't rely on your
instincts alone.'

If you think you know what you’re doing online, take the quiz to find out.