Microsoft Security Essentials Misses 39% of Malware
Barence writes "The latest tests from Dennis Publishing's security labs saw Microsoft Security Essentials fail to detect 39% of the real-world malware thrown at it. Dennis Technology Labs (DTL) tested nine home security products on a Windows 7 PC, including Security Essentials, which is distributed free to Windows users and built into Windows 8 in the form of Windows Defender. While the other eight packages all achieved protection scores of 87% or higher — with five scoring 98% or 99% — Microsoft's free antivirus software protected against only 61% of the malware samples used in the test. Microsoft conceded last year that its security software was intended to offer only "baseline" performance"."
Microsoft Windows hosts 99.999% of malware.
Norton failed to detect itself. That's why it only got 99%.