IF you are good at soldering and splicing wires, go look for a used fan with the SAME set of wires coming from it - either 3 (black / red / yellow) or four. Even an old fan that does not work anymore - you can still scavenge the connector from that. Maybe a computer repair shop.
Simply cut the connector plus some of its wires off the old fan and discard that fan. Trim off a bit of the insulation on the end of each wire. Then go to your fan and trim insulation off the wire ends. CHECK the wire colours carefully - if you're lucky the two sets will have matching colours. Then just use solder to splice each matching colout together, and tape up each joint to insulate.