I never try an update if it does not state very clearly and beforehand what it updates from and to what. Anything else is just a waste of time.Did you try to download the update? IIRC, Zanith uses an installer rather than the loose files most others devs use, it could explain why the files look suspicious to you.
Mediafire and filesfm gave me both very short but identical files which I could not identify.
Meanwhile MEGA is still at ETA >1d. For the compressed version!