Experts at security firm Sophos have branded the US as the "dirty man of the web world" after new research from the vendor identified the country as the top host of infected sites.
Over a third of the world's infected sites are hosted in the US, ahead of Russia with 12.8 per cent and China with 11.2 per cent, according to the Sophos Security Threat Report 2010.
The report covers malicious sites deliberately set up to lure victims with " promises of desirable or salacious content", and the more recent trend of infecting legitimate sites with malware via SQL injection or other attacks, said Sophos senior technology consultant Graham Cluley.
"Webmasters need to take much better care of their sites, ensuring that they are securely coded and properly patched against hackers injecting malicious software into their pages," he wrote in a blog post.
"Meanwhile, all computer users should be protected by a security solution that scans every webpage visited, and every link clicked on, to see if it could contain dangerous content. You scan your email for viruses, and you should do the same for web sites."