How to cash a check made out to my mothers estate and I am not the executor and there is no executor ?

A company contacted me in regards to some money owed to my mother that is deceased . At the time of her death there was no probate and no executor and no will. Myself and my brother just split everything that was left and went on about our business . Now I’m receiving a check that says to the estate of my mother . There is no executor? I’m the beneficiary . That’s it. I’m her son and anything owed to her is no owed to me. How do I cash the check . I’m not jumping through any legal hoops or hiring a lawyer.