Where does one find this mod?

The only shader mod you'd want for a vanilla playthrough is Shaders Max since it looks like vanilla and makes the shadows work properly on widescreen resolutions without messing around with console commands.

Even though the best way theoretically of playing Anomaly is putting together your own modpack, there are a ton of custom pre-assembled alternatives out there if you don't have the time and/or energy to fiddle yourself. Not just G.A.M.M.A. or EFP, although I know those are the most popular ones.

Vanilla Anomaly is great and all but there is so much more to it than that.