The problem is, is it an anomaly or just a very low definition photo? Later photos of the Moon were much higher in definition. The problem here is it is too difficult to make anything out. I am one to believe that there is a strong possibility that aliens have a base on the Moon as there are a lot of resources they could mine and use. It could be a base where they can send ships to observe Earth also.
Looking at the photo, it may or may not have been tampered with by NASA. That is the main problem here, and until any really good photos of structures on the Moon show up, this is all conjecture.