One third of websites harbour malware, according to a recent security threat report by Sophos. Worse still, only 20% of the web pages deliver constructive content. The security company said that 28.8% of websites attempted to install malware on the PCs of trusting users, 19.4% sent spam, 4.3% contained illegal content such as pirated software, and 28% delivered pornographic content. Therefore, only 19.5% delivered constructive content.