MS supported by Google have fixed a big security gap of Windows Defender. Vulnerability was found by IT specialist of a search engine company. It was happened previously that Google experts help MS to fix some bugs. However, they did publish nothing about security hole for the first time. Indeed, info release before fixing problem has already caused disapproval of both MS company and users. Therefore, this time Google transferred all data to MS privately.
A gap was present in MsMpEng emulator. One is used to run dubious files for verification. A vulnerability allowed viruses to intercept emulator control through a special code. As a result, viruses may have get access remote computers. Now Microsoft experts completely fixed this problem.