"Morality (from the Latin moralitas "manner, character, proper behavior") is the differentiation of intentions, decisions, and actions between those that are good or right and those that are bad or wrong." Wikipedia.
When evolution and natural selection evolved the first organisms or "life" certain properties and behaviors were automatically selected for. Such as self-preservation and procreation. From there comes our notion that some things are good and some things are bad. For every organism there are good actions beneficial to survival and successful reproduction and bad actions detrimental to survival and successful reproduction. After all this time, humans are also born with a survival instinct and the instinct to produce offspring. We say murder is immoral and wrong because we are descendants of the first organisms that evolved a survival instinct, not because we subjectively have invented the idea that "murder is wrong".