So far this year, 31 viruses have been classed as a medium risk or higher, compared to 20 in the whole of 2003.
The main factor behind this rise is the battle between the authors of the Bagle and Netsky viruses, who each launched a volley of malicious code containing insults about their rivals. Today, there are still three variants of both Bagle and Netsky that McAfee classes as a medium threat.
An average of 50 new pieces of malware have been released on the Internet each day this year, according to the company, and McAfee is forecasting that by the end of 2004 another 18,000 new pieces of malware will have been created.
"The rise in viruses, worms, Trojans and unwanted programs such as spyware, hacking tools and password stealers in the first half of 2004 has already surpassed what we saw throughout all of 2003, bringing us very close to the 100-thousandth mark for identified threats," said Vincent Gullotto, vice president of McAfee AVERT, the company's antivirus emergency response team.
The forecast for the rest of 2004 and beyond is not heartening. McAfee expects that spyware and adware will become more of a problem, especially spam emails that deposit spyware on a user's PC after they are opened.
Phishing attacks, in which organised criminals attempt to fool people into disclosing their banking details by creating a fake Web site are also predicted to rise - as many users are still blind to the danger of clicking on attachments from unknown sources, according to McAfee.
