I found a bunch of spots on my almost-done-flowering Blue Dream today. So bummed! I trimmed the leaves with the mold, which the guy at my hydroponics store recommended. I put a couple drops of neem oil into a spray bottle of water and gave the air a couple light spritzes to combat the spores (I didn't apply it directly to the buds -- apparently they'll hold the nutty taste and burn black smoke). If your buds haven't flowered, you can buy fungicide from a gardening store and dip the plant in it. I did this with my Skywalker plant and it turned out well.
Make sure to keep the air flow going, get lots of fresh air, and keep an eye on any other plants you have to make sure it doesn't spread.