The Black Viper.

A thug accosts a girl as she leaves her workplace but a man rescues her. The thug vows revenge and, with the help of two friends, attacks the girl and her rescuer again as they're going for a walk. This time they succeed in kidnapping the rescuer. The girl runs home and gets help from several neighbors. They track the ruffians down to a cabin in the mountains where the gang has trapped their victim and set the cabin on fire.