How to Install macOS High Sierra in VirtualBox on Windows 10
 

Whether you want to occasionally test a website in Safari, or try out a little bit of software in the Mac environment, having access to the latest version of macOS in a virtual machine is useful. Unfortunately, you’re not really supposed to do this—so getting macOS running in VirtualBox is, to say the least, tricky.

https://www.howtogeek.com/289594/how...on-windows-10/