Unless, of course, you are David Carradine, in a pine box, wrapped in a wire coat hanger.
Thailand's international tourism trade of sinful delights and medicinal therapies means that the hotel attack could be from anyone from anywhere under the sun.
Its an all access, multicultural, public venue this is available to just about any business class passport holder on planet earth, regardless of their particular predilections or perversions, ulterior motives, shady dealings or illicit appetites.
So in other words, its probably a criminal or spy or government operation. North Korea is unlikely, but South Korea seems an obvious choice since they have the most to gain from Sony's market share.