Last month saw more web-based malware blocked than the whole of 2007, an increase of a third, according to security as a service vendor ScanSafe.

The firm's latest Global Threat Report for July found an increase of 87 per cent in web-based malware blocks from June to July, mainly caused by the increasing use of SQL injection attacks.

July also saw a surge in social engineering-based email attacks, where users are tricked into installing backdoor Trojans and other malware on their PCs. According to ScanSafe, 95 per cent of its customers tried to click on links to malicious sites in these emails.

“This is a pretty disturbingly high percentage; it doesn't speak to anything adverse on the customers' part though, but more the high level of social engineering on the part of the attackers," said ScanSafe's Mary Landesman. "A lot of the emails we saw were masquerading as news alerts from reputable sources such as Google and CNN."

Landesman advised that alongside implementing web filtering technology, IT departments should take on an educational role to "bring the user up to a higher level of understanding" about the nature of current threats.

The ScanSafe Global Threat Report is based on analysis of more than 10 billion web requests scanned each month on behalf of businesses in more than 60 countries, the firm said.