Sniper: Ghost Warrior

Warning! This trophy seems to be glitched for some at the moment.

“The Last Hunt” is found in the challenge campaign. You have to finish the whole mission without firing more than 10 shots. Knifing enemies doesn't count as a shot. This is by far one of the hardest trophies in the game. Take your time to avoid enemies or try to knife them if you really need to kill them. Some people think that shots count up still even if you die. That might be the source of this trophy glitch. Below is a video walking you through the mission:
 

YouTube - Sniper Ghost Warrior - 10 Schüsse Tophäe

Credit to gematria92 for the video.