I bought an MSI R9 280X last Christmas and decided to take it out for some case cleaning (Carbide 300R), to my surprise when I turned it over on the cooler side there was some sort of oily liquid on the shroud. Decided to have a closer look and I saw some residue on the cooler fins too, can someone shed some light on where this mystery oil could've originated from? My PC is completely air cooled btw. I cleaned the stains off the shroud but I can't get to the the stains on the fins themselves.