If you are looking for information on the weapon in Destiny 2 , that is an official in-game item and not related to a .rar file download. Quest: Pick up the "And Out Fly the Wolves" quest from Xur .
The catalyst is obtained by finding three hidden chests guarded by Reaver Vandals within the dungeon. Gjallarhorn-TENOKE.rar
If you are actually looking for the Destiny 2 weapon guide, these videos show the exact steps to get it and its catalyst: If you are looking for information on the