A recently released report claims that Internet Explorer 8 (IE8) is more than twice as effective at blocking malware sites than its nearest rival.
According to NSS Labs Inc., which conducted the Microsoft-sponsored study, IE8 blocked 69% of the 492 malware-distributing Web sites that were included in the survey data. Mozilla Corp.'s Firefox, meanwhile, blocked only 30% of those same sites.
"I was surprised that IE8 did as well as it did," Rick Moy, the president of NSS Labs, said in an interview Tuesday. "But Microsoft has put a lot of effort into security in IE8."
NSS tested six Windows-based browsers -- IE8 RC1, Firefox 3.0.7, Safari 3, Chrome 1.0.154, Opera 9.64 and IE7 -- against so-called "socially engineered" malware: Sites that dupe visiting users into downloading attack code. Typically, the download is disguised, often as an update to popular software such as Adobe's Flash Player.
The tests did not include sites that attack browsers without any user interaction, an increasingly common tactic by hackers who often infect legitimate sites with kits that try a number of different exploits in the hope of compromising an unpatched PC.
To defend against the kind of malware sites that NSS tested, browser makers have been adding anti-malware features to their software. Mozilla, for example, added malware site blocking to Firefox 3.0, which shipped last June.
All browsers that include such a tool -- or anti-phishing tools, which operate in a similar fashion -- rely on a "blacklist" of some sort. The list, which includes known or suspected malware sites, is used to display warnings before a user reaches a site, but after the URL is typed in.
The other browsers trailed IE8 and Firefox in NSS' tests. Apple Inc.'s Safari, for example, blocked 24% of the malware sites, even though Version 3.2 doesn't have an explicit anti-malware tool. Moy said he believed that Safari's anti-phishing tool, which Apple added in November 2008, may have triggered the blocks, since many phishing sites also distribute malware if they're unable to trick users into giving up their identity information through other tactics. "Or maybe Apple started seeding its [anti-phishing] list with malware sites before it launched the beta of Safari 4," Moy said.