How to recognize that a hard cheese is mouldy?
This is what the cheese should look like.



Edges on a cheese like this are referred to as the rind. Any white on there is fine unless it starts looking fluffy, even then you could probably just cut it off. The rind here and on many hard cheeses is a quite hard layer of dried cheese and protects the cheese inside.

If the yellow section of the cheese had mold on it that would indicate the cheese had become moldy after being cut or if there was a blue or green mold growing anywhere on this type of cheese. This would normally indicate the cheese had been kept badly. If your fridge is clean and dry wrapped hard cheese should keep a couple of months.