First time I see something like that, but as there are bubbles, I'd say that the can has somehow started leaking. Probably along the seam between the tube and the bottom parts of the can. Most likely, that seam is sealed in some way with some adhesive/sealant, which has come out along with the propellant gas.
I'd expect that it would not be too unsafe to use the can, as pressing the nozzle will only decrease the pressure on the leak. But then again, I'd also expect the propellant gas to have escaped altogether, so there'll be woefully little paint coming out the nozzle. Still; to be on the safe side, I'd avoid using it altogether.
At any rate: I suggest you bring it back to where ever you bought it and request a replacement or refund, because that is clearly not supposed to happen...
