At the time of writing, the hacker's code attempts to dupe web surfers by running a fake anti-virus scan and displaying a bogus message that their computer is infected with a variety of different viruses and Trojan horses.

The hackers' aim is to scare unsuspecting computer users into purchasing a bogus security product.

The attacks are known as SQL injections and Sophos has warned that it would be trivial for the hackers who have compromised the webpages to alter the payload so that it became more malicious.

This could include code designed to harvest confidential information from users, or turn innocent victims' PCs into botnets, which the cybercriminals could use to launch distributed denial-of-service attacks and spread spam messages.

"There are millions of videogame lovers around the world, many of whom will visit Sony's PlayStation website regularly to find out more about the latest console games,” said Graham Cluley, senior technology consultant for Sophos.

“Most would never expect that surfing to a website like this could potentially infect them with malware.”

Cluley said users need sufficient protection in place or they could find themselves scared into handing over their credit card details.

"It is essential that all websites, especially high profile ones like this, have been properly hardened to prevent hackers from injecting malicious code on to what should be legitimate webpages,” he added.

Cluley said Sophos customers are automatically protected against the threats which Sophos identifies as Troj/Iframe-AG and Mal/Badsrc.