Most Moen faucets have nuts to tighten the faucet. From under the sink, look up where the water supplies attach to the faucet and you will see these nuts. Tighten them with a basin wrench if you want to get it done easily. Otherwise you can use a pair of pliers, it will be tougher but will get the job done. If it is secured with small nuts then use a small adjustable wrench. You might want safety glasses because rust or other debri will get in your eyes.