Internet Explorer 8 detected nearly three times as many socially engineered malware links than Apple's Safari 4 and Mozilla's Firefox 3, according to new test results from an independent security lab.

IE8 blocked 81 percent of socially engineered malware URLs -- those links that appear to be legitimate in order to dupe the user into "downloading" something -- while Firefox 3.0.11 caught 27 percent; Apple Safari 4.0.2, 21 percent; Google Chrome 2.0.172.33, 7 percent; and Opera 10 Beta, only 1 percent, according to a new round of browser security feature tests by NSS Labs.

Both IE8 and Firefox nearly equally caught most phishing sites: IE8 detected 83 percent of them, while Firefox 3 caught 80 percent. Opera 10 Beta stopped about 54 percent, while Chrome 2 blocked 26 percent, and Safari 4 just 2 percent.

So how did IE8 fare so much better in nabbing socially engineered malware threats? "The difference is the reputation system in the cloud," says Rick Moy, president of NSS Labs. "It comes back to Microsoft's resources."

Amy Barzdukas, general manager of Internet Explorer, concurred. "We have tremendous reach," she says, including Microsoft's opt-in program for customers that gathers real threat data, and Microsoft's global security response organization. "The [customer data] feedback and telemetry gives us visibility on what's going on worldwide in a very significant way," Barzdukas says.

In NSS Labs' previous test of the browsers back in February, IE8 caught 69 percent of socially engineered malware. Barzdukas attributed the 12 percent jump to the latest version of IE8 being the final release version.

Firefox 3 and Safari 4 dipped slightly from earlier in the year, about 3 percent, but Chrome went from catching 16 percent of socially engineered malware sites earlier this year to 8 percent in July, and Opera 10 Beta from 5 percent to 1 percent.

"Chrome 2 performed very consistently, albeit very poorly. Chrome 2 lost the most ground compared to Internet Explorer 8 over the two tests, declining 8% and blocking 74% fewer malicious sites than the leader," the NSS Labs report says. "Users should not expect any protection against socially engineered malware from Opera 10 Beta."

Meanwhile, this type of malware is on the rise. "When we added protections against socially engineered malware in IE8, we were even surprised at how much malware it was catching -- we expected it would catch a lot, but we didn't expect it to catch 20 times as much malware as phishing sites. That speaks to the increase in socially engineered malware," Microsoft's Barzdukas says.

In the phishing test, NSS found that Chrome's 26 percent rate of detection was "below average," even though Firefox 3 also deploys Google's SafeBrowsing API. "We expected better results given the fanfare about Google's SafeBrowsing Initiative," the report says.

NSS Labs' Moy says he was both disappointed and encouraged by the test results. "I didn't expect the low watermarks to be as low as they are. But I didn't expect the high ones to be as high as they are," he says. "I was pleasantly surprised with IE8, and Firefox did a good job on phishing."

He says browser vendors can do more using reputation systems as an extra layer of security. "And the takeaway from these reports is enterprise security managers can now make a decision on which browser to recommend to their corporation," he says.

NSS Labs conducted the live tests around the clock during a 12-day period in July. Moy says the tests not only pitted the browsers head to head against one another, but also tested them against the bad guys. NSS plans to perform another round of browser tests next quarter, he says.

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