Enabling Microsoft Defender

This is an anti-virus and advanced threat protection feature that is free and built in to your Windows 10 platforms.

Windows Defender Antivirus: Your next-generation protection

Windows Defender Antivirus is the next-generation protection component of Microsoft Defender Advanced Threat Protection (Microsoft Defender ATP). Next-generation protection brings together machine learning, big-data analysis, in-depth threat resistance research, and the Microsoft cloud infrastructure to protect devices in your enterprise organization. Next-generation protection services include the following:

To enable this follow these official Microsoft instructions