First you need to stop the moisture coming up from your floor. Wash down with bleach water or spray with mold killer. Use a dehumidifier but find out your moisture source and fix. Hopefully you don't have carpet down. May have mold growing under flooring.
Since it's in the house call the pros. I worked for hurricane recovery and mold or mildew of any kind is insidious, and potentially DEADLY. For any you see on the walls there may be much worse sections you can't. If the mold was caused by a specific incident it may be covered by your home owners policy. Give them a call.
You have a moisture problem. I will assume that there is an uninsulaed unheated space below the baseboard. Warm air in the room hits the cold baseboards and condensation forms allowing mold and mildew to grow. You need to solve the moisture issue or the mold will come back.
a mixture of bleach and water will wash the mold away. A mixture if vinegar and water will kill mold spores. Do not mix bleach and vinegar.
Go buy you some Lysol disinfecting aerosol spray and spray it down. Let it sit for a week. Use warm soapy water to remove and keep an eye on the area and periodiocally spray the Lysol disinfecting spray if needed.
We use it in our shower to keep the shower from growing mildew. Works great!