Cloudy white vinegar
Mother of vinegar is a the bacteria acetobacter, which produces vinegar from wine, beer, or any other alcoholic source. In vinegar production, if the mother eats all the alcohol, it will then eat the vinegar and convert it into carbon dioxide. Vinegar mother will turn vinegar cloudy, and will form a film on the surface of the liquid. My guess is some acetobacter found its way in to your vinegar. It is harmless, but will lessen the strength of the vinegar over time. Vinegar mother also likes to live in warm places. It's best to store vinegar in a cooler place, like a pantry.