Director Brad Anderson and the crew of the movie Vanishing on 7th Street introduce us to the film:
From the video above and thanks to John Leguizamo we get to guess where the spooky shadows may come from:
"When I read it, I was really creeped out and scared in my own house. It's things that you really think about… [...] all the stuff we talk about, the anti-matter, smashing particles at CERN in Geneva, are all really happening now Brad has added an extra layer with actual facts."
Actor John Leguizamo
From what he's saying, those shadowy figures that are wandering in the darkness come from a science experiment gone awry... Hmmm, do they come from another dimension? Well, don't want to speculate further, let's wait for the movie trailer of Vanishing on 7th Street.