Be sure to install the Virtualbox Extension Pack to view USB drives from your virtual machine. Alternatively, y ou could install Mavericks on a virtual machine, and run Unibeast on there instead. You could use a real Mac, if you own one.
Be sure to read the Hackintosh compatibility guide very carefully, to check whether or not your computer qualifies. A compatible computer: Not every computer will work with Mac OS X, even with the help of tools like Unibeast and Multibeast.This guide will follow tonymacx86's standard Unibeast method , except that we try to cover the process with more detail (and pictures!). Right now, the newest iteration of OS X is 10.10, known as Yosemite. Installing Yosemite on a PC is pretty much the exact same as installing Mac OS X 10.9 (Mavericks). If you're interested in running Mac OS X, but you don't want to pay ridiculous prices for a normal Mac, then a Hackintosh just might be for you.