The Register reports Microsoft's free Security Essentials anti-virus software has lost its seal of approval from AV-TEST. The German test lab conducts bi-monthly tests and claims Security Essentials lost its rating because it now has a zero-day detection rate of only 64 percent, well below the industry average of 89 percent.
Security Essentials has lost AV-TEST’s seal before, with its September 2010 test failing to meet the lab’s criteria. It is the only one of 24 AV products for Windows 7 without the certification. Four products missed out for Windows Vista and two for Windows XP. Windows 8 AV tools are yet to go under the microscope and Microsoft is absent from AV-TEST's list of vendors thanks to the new OS' integrated protection software.
While tests like these have no official standing, a look at AV-TEST’s longitudinal analysis of Security Essentials show it has consistently struggled to perform well in its malware detection and blocking tests.