Antimalware Engine 1.1.10003.0 was released to customers on 18 November 2013
Antimalware Engine 1.1.10100.0 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 18 November 2013. Signature package 1.163.0.0 is the first that contains this engine.