How to get hold of 3D World Studio

I wan't to start modding SCP: containment breach, and to start, I want to make custom rooms with 3D World Studio. Problem is that I CAN'T find a download to it, all sites are sketch af, and others, just don't work at all. If anyone has a free copy or any other way of getting it, that would be a tremendous thank you on my part. :)