Microsoft's Internet Explorer 9 browser is far better than its rivals at combating socially engineered malware, according to a study by researchers at NSS Labs.
The security company published its latest browser analysis (PDF) on Monday, showing that IE9 was able to successfully filter almost every malicious website and program thrown at it. Chrome was in second place with a 13.2-percent success rate, and Opera was at the bottom with just 6.1 percent.
Socially engineered malware, which users are generally tricked into downloading, is now much more prevalent than malware distributed by email, the security company said.
In its analysis, which was not sponsored by an outside company, NSS Labs said IE9's filtering showed a slight improvement on IE8. Both browsers use Microsoft's SmartScreen URL reputation list to identify dodgy web pages, but the addition of an application reputation warning system in the new browser took IE9's blocking rate to 99.2 percent.
Microsoft's application reputation list is dynamically created and maintained in much the same way that search engines create and maintain content lists for search purposes, NSS Labs explained.
"The significance of Microsoft's new application reputation technology cannot be overstated," NSS Labs's report read. "Application reputation is the first attempt by any vendor to create a definitive list of every application on the internet. This new capability helps users discern malware and potentially unsafe software from actual good software."
The significance of Microsoft's new application reputation technology cannot be overstated.– NSS Labs
Even with the application reputation technology disabled, IE9 still managed a unique URL-blocking score of 89.5 percent and an over-time protection rating of 96 percent.
"Enabling Application Reputation on top of SmartScreen increased the unique URL block rate of Internet Explorer 9 by 10.4 percent (to 99.9 percent) as well as the over-time protection by 3.2 percent (to 99.2 percent)," NSS Labs said.
Microsoft was delighted at the results, and its product marketing director Roger Capriotti said the effectiveness and speed of the company's anti-malware technology had improved, meaning "fewer infections and headaches" for customers.
"We continue to improve the quality and protection SmartScreen technology offers to our Internet Explorer users," Capriotti wrote in a blog post. "You can see these improvements in how much faster SmartScreen is in blocking malware over time. Since the October 2010 NSS report, the average time taken by SmartScreen filter to block a threat has gotten 28-percent faster — and if application reputation is considered, then the average time has improved by 85 percent."
In the NSS Labs tests, Firefox 4 and Safari 5 both scored 7.6 percent for filtering malware over time, while Chrome 12 scored 13.2 percent. All three of these browsers use Google's Safe Browser feed, but Chrome 12 also includes warnings that pop up when potentially malicious files are about to be downloaded.
The security firm carried out its tests in April. Since then, Google has released Chrome 13 and Mozilla has released Firefox 5. Both browser updates include security fixes, but neither introduces any major new security technology.
According to recent statistics, variants of IE still command a 53.7 percent share of the global browser market. Firefox is at 21.7 percent, Chrome at 13.1 percent and Safari at 7.5 percent.
Opera, which came bottom in NSS Labs's tests with a 6.1-percent over-time success rate, has 1.7 percent of the global browser market.
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