Kriegsmarine was (in)famous for the massive use of their submarine’s fleet during the War, despite most of the U-boats were used against Allied shipping, some were deployed against the Soviet Navy. That’s the list of the Soviet anti-submarines successes.
NOTE: this list include also U-boats lightly damaged in action. This kind of damage was often a success because could force the submarine to abandon a patrol.
A submarine with the holed periscope can’t attack a merchant after all! Many merchants were potentially saved attacks that caused this kind of damage.
2 U-boats surely sunk by Soviet forces (one by submarine, one by depth charges) with other 4 of uncertain loss. At least 3 U-boats suffered soviet attacks with heavy damages as result (caused by depth charges and ramming) and needed time to be repaired.
In Arctic, the Soviets made successful use of Allied Lend-Leased ships (destroyers and minesweepers) and aircrafts (Catalina and B-25 Mitchell), against German U-boats.