According to the results of a two-week study of Windows Defender by Webroot, a leading antispyware vendor and Microsoft competitor, the product missed 84% of a sample set of 25 spyware, Trojan horse programs and keyloggers. Many of the samples were unable to install on Vista and simply crashed, but others got through just fine. Webroot"s Spy Sweeper product spotted all of the samples.
Gerhard Eschelbeck, Chief Technology Officer at Webroot, said the point of the study was not to draw specific conclusions. He acknowledged that 25 samples was a tiny fraction and that it may be possible for Microsoft or other competitors to pick samples of malicious code that would evade Webroot"s Spy Sweeper. "It"s important to leave the interpretation up to individuals. People need to make their own conclusions about it," he said. Eschelbeck noted that Microsoft should update Windows Defender quicker than on a weekly basis. Webroot has been hurt by Microsoft"s entry into the desktop and enterprise security business and the company"s decision to offer Windows Defender as a free download.