Looks like early fungus to me, the blooming around the edges of the specks makes me think that, but there is no spider webbing yet so it is unlikely to be a serious issue. I wouldn't risk contamination of my other lenses so keep it away from them, don't put it in the dark, fungus hates the light.
I would find a local camera and lens repairer, it is a very simple fix for somebody with basic camera maintenance skills and they will be much cheaper and faster than Canon at sorting it out.
Fungus often affects rarely used lenses, like I said it loves dark moist environments. Use it infrequently, clean it every time you go to put it away without fully drying it and that is a recipe for fungus.