The answer depends on many things and none are very pretty.
Cinder Block transfers moisture easily. It was, unfortunately, a common way to build homes in Ireland for many years so I do have some experience with it.
Easy answer: Cover the mold with the shellac based primer "Kilz" and paint. It won't be gone but it won't get through to the inside for quite a long time.
Long answer: Depends on where the mold is most common:
1. All along all walls, particularly upper sections, indicates moisture coming in from the roof.
2. Along lower walls indicates the home was built with a foundation not far enough away from the ground (normally 6" required in US) and moisture is coming from ground level and the walls were not sealed properly.
3. Along only weather walls; normally west and north. This is where rain normally comes from and this could be fixed with a better exterior surface.
Mold, once it arrives cannot be gotten rid of. It's a persistent beast. It lives in the walls even in dry weather and grows and re-appears when it has moisture.
Seal the moisture from and to the walls as best you can. Procedure can be anything from tar based coating as treating a retaining wall or heavy mill plastic to seal it from the inside.
Cinder block is a very inexpensive manner to build homes. The exterior walls should be treated the same as any retaining wall, coated against moisture.
If I only knew what I was doing!