I adjust the dark pics (all my cameras) with "Photoscape’.
You just keep clicking “back-light” in edit mode till you can see what your want.
You can pull stuff out of completely black photos (but can not fix white-out pics).
Under exposed is no problem, but you can’t do anything with over exposed.
This works well with attic - crawlspace photos which have a dark background due to distance and limited flash distance.
This is what I got out of your posted pics. You can do much better with full resolution pics not posted to the MB.