Definite mold on the cigars. You can try using a cutter and cutting off about 1/4 inch from the foot. If you still see mold then try a little further. If you see no mold you should be ok.
As far as the humidor goes, I can't say for certain but I would definitely err on the side of caution. You have said that you have wiped them down with alcohol already. You may want to wipe again and also set them out in the bright sunlight.