Antimalware Engine 1.1.10501.0 was released to customers on 15 April 2014

Antimalware Engine 1.1.10501.0 was released to all Microsoft Security Essentials, Forefront Client Security, Forefront Endpoint Protection, Windows Intune Endpoint Protection, and Windows System Center Endpoint Protection customers on 15 April 2014. Signature package 1.171.0.0 is the first that contains this engine.