Apollo 18/WMG

Apollo 18 is the prequel to Transformers: Dark of the Moon.
As someone stated in the Headscratchers for the movie, the footage was recovered by Optimus Prime when they went to recover Sentinel Prime.

It also explains why the "aliens" were disguised as rocks, as they had yet to assimilate any humans to be able to copy them. However, after, well...

Everything they did was being broadcast back to earth, live.
This explains how the video got back to earth. They may not have been watching it all as it came in, maybe it was scrambled for the DoD.

Apollo 18 is a prequel to Resident Evil 4
The rocks on the moon are strain of Las Plagas adapted to space. Another meteor fell in Notspain during the middle ages and its plagas developed into the strain that appeared in Resident Evil 4 and 5