It might not be mold but something that broke free from the bottom and got over everything.
I know that mold does grow in the vent portion of the dishwasher - that happens when you close the door completely....when you have dirty dishes in it.
You can buy "dishwasher cleaner" it's a white bottle with a blue lid at your grocery store - run it once through - it should help! NO DISHES may be in your dishwasher when you do this.
If that doesn't help - run it again.....if your husband is a handyman - have him pull out the bottom rack, unscrew the bottom rotater blade and remove any gunk there!!