I believe I have spectated a Wall hacker here with what seems to be damage mod or shooting through walls.

*Full Video , 1 Section Cut as Shadow play had , "Show desktop on"  i Tabbed out to check user name change .

Note a few minutes in he's on snow into C stairs  shoot's through solid cement .  Shooting through Cement

Later he's on main floor C  and peppers wall for C stair stack and gets a kill through wall again : Though Wall #2