A study by security firm BitDefender revealed that Windows 8's built-in security manages to block 85 percent of the 100 malware families most used by cybercriminals this year. It's not a perfect score, but significanty better than Windows 7's out-of-the-box security which manages to block just 32 percent of malware. Full details at Neowin.
Security-wise, things don't look so bad for Windows 8 and the new measures implemented by Microsoft. Security firm and anti-virus maker BitDefender recently performed a number of tests on the stock, out-of-the-box Windows 8 configuration and concluded that just 15% of "the 100 malware families most used by cyber criminals this year" managed to infect the system.
Of course as BitDefender makes anti-virus products they tried to spin this by saying Windows 8 is "prone to infection by leading malware threats", but really, blocking 85% of threats with just Windows Defender enabled shows that Microsoft's in-house and bundled solution is quite effective. BitDefender tested 385 of the most popular malware samples, and 61 of those infected the system.