Windows 7's malware infection rate climbed by as much as 182 percent this year, Microsoft said today. But even with that dramatic increase, Windows 7 remained two to three times less likely to fall to hacker attack than the aged Windows XP.
Data from Microsoft's newest twice-yearly security report showed that in the second quarter of 2012, Windows 7 was between 33 percent and 182 percent more likely to be infected by malware than in the second quarter of 2011.
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The infection rate for Windows RTM, or "release to manufacturing," the original version launched in Oct. 2009, was 33 percent higher this year for the 32-bit edition (x86), 59 percent higher for the 64-bit (x64) OS. Windows 7 Service Pack 1 (SP1) -- the upgrade that shipped in February 2011 -- saw even larger infection increases: 172 percent for x86, 182 percent for x64.
Microsoft blamed several factors for the boost in successful malware attacks, including less savvy users. "This may be caused in part by increasing acceptance and usage of the newest consumer version of Windows," said Microsoft in its latest Security Intelligence Report. "Early adopters are often technology enthusiasts who have a higher level of technical expertise than the mainstream computing population. As the Windows 7 install base has grown, new users are likely to possess a lower degree of security awareness than the early adopters and be less aware of safe online practices."
But other elements came into play, argued Tim Rains, director of Microsoft's Trustworthy Computing group. "There are several factors at play here. In XP, for example, we've seen infection rates go up because of particular pieces of malware that are more effective on that platform," said Rains in an interview. "[And] in different places in the world, [users'] ability to keep Windows up to date varies greatly."
For the first time, Microsoft ranked the threats facing each version of Windows, bolstering Rains' assertion that some malware families are more successful against, or at least more often aimed at, specific Windows builds, and thus affect the infection rates.
But security researchers were more likely to pin the blame on Windows 7's popularity. "Windows 7 has really been the first platform adopted by both enterprises and consumers, and that kind of adoption hasn't happened in quite some time for Microsoft," said Andrew Storms, director of security operations at nCircle Security. "Given the market movements, its likely that the attackers follow."
And Windows 7 is a more popular operating system this year: From June 2011 to June 2012, Windows 7's usage share grew 45 percent, according to statistics from metric firm Net Applications.