A sophisticated worm designed to steal industrial secrets has been around for much longer than previously thought, according to security experts investigating the malicious software.

Ten years ago today, on May 4, 2000, a security team with MessageLabs, a provider of messaging security services, came in to work and discovered the number of viruses its system had intercepted in the last several hours was off the charts.

A computer worm that China warned Internet users against is an updated version of the Panda Burning Incense virus, which infected millions of PCs in the country three years ago, according to McAfee.

Some Facebook users have been infected with a worm after clicking on an image of a scantily clad woman, which then redirects the victims to a pornography site, according to security researchers.

The first worm written for Apple's iPhone has been unleashed and is infecting phones in Australia.