Windows Defender Antivirus, Microsoft Endpoint Protection and Microsoft Security Essentials antimalware solutions are crashing randomly with a 0x800106ba error code on computers running Windows 7, Windows 8.1, and Windows Server 2003, 2008 and 2012. Microsoft confirmed that this is a global issue and is working to develop a fix according to Windows users who filed support cases, with the problem to be fixed in the next definition update version (1.289.1573.0) expected to be available in a couple of hours.
Source: https://www.bleepingcomputer.com/news/security/microsoft-antimalware-crashing-with-error-0x800106ba-on-windows-7-and-8/