Over 9,500 new malware-infected web pages are being discovered every day, and many of them are unknowingly hosted by legitimate web sites.

Security experts at Sophos identified 304,000 malicious web pages in May. There were 1,000 more pages being discovered each day in May than there were in April.

The most common form of malware discovered was Iframe, which infects legitimate web pages with malicious code.

Many of the sites that were unknowingly hosting dangerous pages were government organizations and other businesses.

China remains the country with the biggest share of malware pages, responsible for hosting more than 50% of infected web pages identified by Sophos.

E-mail-based malware threats continue to be a problem, with the most common being the Sober worm which spreads by sending itself to e-mail addresses found on the infected computer.

The top hoax mail currently being spammed out is the Hotmail hoax which tells users they will lose their account unless they forward the message to other users.

Meanwhile, US authorities have arrested a 27-year-old man whom they claim is one of the world's biggest spammers. Robert Soloway used infected computers to secretly send out millions of spam e-mails.

Related Tip: Preventing Spam