In its most recent reports
, AV-Test had very few flattering things to say about Windows Defender. Microsoft's security suite was rated as the seventh best antivirus product in the independent test. In total, 15 AV products were tested. Microsoft, however, has now disputed AV-Test's methodology and conclusion
. For some context, the top AV products rated by AV-Test on Windows 10 were Trend Micro, Vipre, AhnLab, Avira, Bitdefender, Kaspersky, and McAfee.
Windows Defender was able to detect 100 percent of new and old malware, but it lost few points for performance (which, AV-Test measures on the basis of how a security suite slows applications and websites on the test computer); and usability (which counts false-positives or instances where AV wrongly identifies a file as malicious.) From a report: Windows Defender's performance rating was dragged down because it slowed the installation of frequently used applications more than the industry average, and wrongly detected 16 pieces of legitimate software compared with the industry average of four. But Microsoft wants enterprise customers to know that Windows Defender is only half the picture, given the option for customers to also deploy Windows Defender Advanced Threat Protection's (ATP) "stack components" including Smartscreen, Application Guard, and Application Control.
In the January and February test Windows Defender also scored 100 percent on protection. However it did miss two samples. Since then it's retrained its machine-learning classifiers to detect them. But Microsoft notes in a new paper that Defender ATP did catch them, which isn't reflected in AV-Test's or other testing firms' result. Microsoft hopes to change this so that testers include so-called stack components available in ATP. "As threats become more sophisticated, Microsoft and other security platform vendors continue evolving their product capabilities to detect threats across different attack stages," Microsoft's Windows Defender Research team writes. "We hope to see independent testers evolve their methodologies as well. Our customers need greater transparency and optics into what an end-to-end solution can accomplish in terms of total preventive protection, including the quality of individual components like antivirus."