do we know the covenants point of origin?

have I maybe missed it or has it been said where the covenant is coming from? could help in developing motive, as in if it originates from earth it could be a set up from the very begining on the part of the company. could also answer, if others r correct, whether ripley is indeed/possibly the daughter of daniels. was walter always onboard or was the ship intercepted onroute somewhere else and walter put on board?