What molecule??
I'm assuming the answer would be by diffusion.
A light that shines in all living things
It depends on which virus you are referring to specifically. Viruses come in many shapes and types; their variations are tremendous.
For HIV and Influenza, viruses acquire their envelops after maturation, during the budding off or detachment stage from the host cell.
Hope this helps! :)
To survive natural selection, one must be fit and be able to adapt to the environment and situations, thus why it's called survival of the fittest.