> How on earth can the software recognize the virtual environment?
VirtualBox, VMWare and other VM software contain special features for
accessing the VM software from the guest. That's how guest additions can
be used to enhance the functionality in the guest (transparent mouse and
keyboard integration, special video drivers for resizing the screen area
to near-arbitrary values, etc.).
The methods used by guest additions can be used to detect execution in
the virtual environment, and act upon that.
Lionel.