That's a serious case of Google-Image-Searchitis. My theory: somebody googled for "settings icon", swore to himself to get proper artwork later, forgot, and there we have it. (Yes, I'm guilty of that too, but I usually don't forget)
What search terms do you use to get this particular icon returned? [settings icon]["settings icon"][free settings icon] etc don't return it.
Iconfinder is one the most popular ones around... so probably whoever is "responsible" for it used that kind of search engine.
There it is: http://www.iconfinder.com/icondetails/8844/128/kit_settings_... with author, licence and all the info.