"Web browsers remain the primary infection vector for most consumers and enterprises. Improving the browser's malware block rate substantially impacts one's security profile," said NSS research director Randy Abrams.
The results suggested that Google's Chrome - and the other browsers taking technology from Google - was still over-reliant on less effective reputation technology than was being used by Microsoft, he said.
"The net result is that IE 10 users are offered superior protection over Chrome users with one quarter the risk of making a bad download decision. Firefox, Safari, and Opera users are afforded little protection at all by their browsers."
NSS Labs tested IE10's performance on Windows 8; the same App Rec system was also available to Windows 7 users running IE9 but it was unclear whether this would show the same protection, the firm warned.
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