Malmuth began making documentaries while serving with the U.S. Army Signal Corps, where he met baseball announcer Walter Red Barber.
After his military career, Malmuth directed the New York Yankee games at WPIX radio before entering the film and television industry.
Malmuth's directoral debut was Fore Play, an anthology comedy film which he co-directed with John G. Avildsen.
He was best known for directing Sylvester Stallone in the 1981 thriller Nighthawks and Steven Seagal in the 1990 political action film Hard to Kill and The Man Who Wasn't There, starring Steve Guttenberg.
He also worked on the television series Beauty and the Beast and the Emmy-winning ABC Afterschool Special A Boy's Dream, which featured Darryl Strawberry.