'wrong' is so subjective (like bull said).
i think the concepts of "right" and "wrong" have to carry the idea of whether an action will have a positive or negative effect on your immediate society...whether it advance your culture forward or push it backwards. but then again "forward progress" is also subjective. ultimately, even murderous terrorists are trying to exterminate those that in their opinion are "unworthy" to make way for a peaceful, utopian society (or effect policy change to ultimately lead to the same outcome). so, its my belief that a utopian society is a primary desire of all humans. if that's the case, then only actions that bring us closer to that reality can be considered catalysts for positive cultural change and therefore "right" (i.e. "not wrong").
this would mean (in my small opinion) that murder is wrong. personally, i choose to live my daily life as if the world were already a utopian paradise, although it is far from.