You do need to address the leak... but even tight a/c systems can have mold problems... and odors.....
One method that has worked for me is, while it is on, find the intake (usually near your feet on one side) and spray a good shot of Lysol aerosol at it ... be sure the blower is on high.....it may take several applications over a couple of days... but it really works.... also had good results from spraying Fabreez into the air stream at the same place...
Be sure to clean out your condensation drip tube...and spray it also....and make sure it will let water out...