The Nacene are a non-corporeal species that exists within subspace and has the ability to manipulate it. They're known for transporting beings and vessels from one quadrant to the next, over thousands of lightyears of space. It is possible a similar species has this capability, in addition to being able to penetrate the space-time continuum, as well as parallel and alternate universes.
[ and then there's the q, but this seems far too... organized to be a construct of the continuum. ]