It! The Terror from Beyond Space-Marshall Thompson, Shirley Patterson-1958 IMDB 6/10

The first manned expedition to Mars is marooned; by the time a rescue mission arrives, there is only one survivor: the leader, Col. Edward Carruthers, who appears to have murdered the others! According to Carruthers, an unknown life form killed his comrades during a sandstorm. But the skeptical rescuers little suspect that "it" has stowed away for the voyage back to Earth...