You should be able to have VirtualBox use your host computer's network interface by going into the settings menu for your VM (the large gear button at the top of the main VirtualBox window if you're using the GUI), going to the Network section, and under the "Attached to" menu, choosing NAT (this bridges the VM's network interface to your host's..at least that's my understanding of it).
Hope that helps
If NAT doesn't work, then you can try the other options and see which one works out.