In a small bowl, stir together ketchup, molasses, vinegar, Worcestershire sauce, sugar, mustard, hot sauce and liquid smoke.
Place pork ribs in the slow cooker insert and pour 1 cup sauce over top, reserving the rest for later. Cover and cook on HIGH for 6 hours or LOW for 9 hours or until very tender.
Remove ribs from slow cooker and brush with reserved sauce.