Microsoft released an emergency fix yesterday Monday May 8th to address the critical security vulnerability in the Microsoft Malware Protection Engine which affects a number of Microsoft products, including Windows Defender, Windows Intune Endpoint Protection, Microsoft Security Essentials, Microsoft System Center Endpoint Protection, Microsoft Forefront Security for SharePoint, Microsoft Endpoint Protection, and Microsoft Forefront Endpoint Protection. These tools are enabled by default in Windows 8, 8.1, 10, and Windows Server 2012
An attacker who successfully exploited this vulnerability could execute arbitrary code in the security context of the LocalSystem account and take control of the system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights