Virtual Machines as Sandboxes

[longshot]

I'm a newbie to the whole virtual machine thing so please forgive my naiveté.

In connection with some classwork, I recently installed VirtualBox with a Linux guest and a Win XP 32 guest on my Win 7 64 system. When I use them for browsing I have anti-virus software installed on the vm.

It seems to me that using a virtual machine as a 'sandbox' to insulate your computer is very strong protection. If you pick up a nasty on the virtual machine you can simply reset(or reinstall) the infected machine to an earlier state and the nastys go away.

This assumes that you don't copy or move any downloaded materials from the virtual machine's virtual hard drive to a host folder.

Are there dangers of 'leaks' from the virtual machine to the host machine? They obviously have to share physical memory and disk space.

Thanks in advance.
longshot

[daemon]

You are right, this is a very strong protection. You should keep your virtualization software current though. There were vulnerabilities in VMWare in the past that allowed Guests to break out into the host system (see http://www.securityfocus.com/brief/688).

While VirtualBox was not affected by such a security problem yet (as far as I know), it still is possible in the future.

daemon

[Tom.K]

I guess that's why most people use VirtualBox. I use VMWare Player, but i run it with sandboxie which should do some improved security.