https://www.theregister.co.uk/2018/02/12/microsoft_windows_atp/

Microsoft has back-ported its Windows Defender Advanced Threat Protection (ATP) antivirus tool from Windows 10 to Windows 7 and 8.1.

The release will allow those holding out with older versions of the OS to get some of the same exploit and malware-infection prevention and event reporting features it offers on Windows 10, particularly when used with Windows Defender.