Is this Mold

Yes, it's mold. Bleach and water will kill it.

Yes sure, it is the presence of mold. But it must be removed before it will grow in larger one.
Here are few steps to remove them
Step-1
Prepare a solution of chlorine bleach & water :-
Step-2
By taking one part bleach to 3 parts water – or get hold of a household detergent like Domestos bleach spray with bleach as an active ingredient.
Step-3
Using a stiff-bristled brush, scrub the infected area. Rinse thoroughly and dry.

It is