McAfee claims the biggest source of adware are celebrities websites.
Using a web ranking utility called SiteAdvisor, McAfee has examined tens of thousands of websites for adware and spyware-like characteristics. It is commonly believed that adult websites are the main spreaders of adware, but McAfee says this is a misconception. "Celebrities are a bigger lure than sex," said the McAfee report.
According to McAfee, the celebrities may not even be aware that their websites are spreading adware because the adware companies use front companies to hide themselves. The front companies also make it hard to tell if a website is safe or not. McAfee recently surveyed web surfers and found that 97% of Internet users could not differentiate between safe and unsafe websites.