Malware VS Router under VirtualBox

[Spartacus1]

Hello to all who read!
I am wanting to test out some malware on my winxp vm.  I am using OpenSUSE 11.4 as my host and VirtualBox as my emulator, but I have some other machines running Win XP and Vista on the same router.
How likely is it that my router will get infected and spread to my other machines?
Thanks!

[MysteryFCM]

It's not the router you've got to worry about - it's the other machines (especially if they've got file sharing enabled).

When doing this, always ensure the machine is isolated (i.e. on a different subnet for a start).