They are molex connectors. And where to get them depends on their configuration - I believe that you will need to get ones that match both the number of connectors AND the shape configuration of those connectors (the plastic shape).
The name should at least get you moved forward a bit.
(And, just in case, these aren't meant for multiple connect/disconnects...if your thinking of using them for that you might want to check DB cables/connectors instead...)