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 killing the crews of the Soviet and American vehicles
- taking it one step futher the so called "aliens" were deployed by Soundwave to kill any humans that tried to go back to The Ark.
- "Humans Inferior,Soundwave superior"
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 Do D
- Unfortunately for that theory, live lunar broadcasts couldn't capture full-motion, full-resolution 16mm quality. Or at least, that's what They tell us.
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
- Alternatively, Las Plagas are native to the Moon and were introduced to Earth by a chance meteor strike which knocked some of them loose millions of years ago (hence the Plaga fossils underneath Salazar's castle).
- As another alternative, they share a common ancestor in primordial microbes which were separated by the formation of the Moon before almost any other life form.
(As, of course, was Clover
The aliens weren't just disguised as rocks. Just like the Necromorph moons from Dead Space 3, our moon is made of undead alien monsters.
Luckily (hopefully), we don't find this out thanks to the government keeping it under wraps, but we do encounter similar things once we colonize space...
The Doctor and Clara are gonna face down moon spiders. Could it not be any more obvious?!?
On that note...
These were the "Moonites" Strax was warning us about!
It was her idea of fun.