Hello!
Here is a list of Pokemon that give out Attack or Special Attack EVs in ORAS.
Granite Cave B2F
Sableye (AS only): 1 Atk (+1 Def) - 5%
Mawile (OR only): 1 Atk (+1 Def) - 5%
New Mauville
Magnemite: 1 SpA - 35%
Fiery Path
Slumga: 1 SpA - 5%
Route 12
Numel: 1 SpA - 65% (Note: Numel Can also be found in Fiery Path at a 60% chance of spawing)
Machop: 1 Atk - 35%
Meteor Falls
Bagon: 1 Atk - 5%
Route 119
Oddish: 1 SpA - 100% (Note: Oddish can be found in the Safari Zone at 35%, on Route 120 at 60%, or Route 117 at 60%. With the latter, a Zigzagoon is a guaranteed spawn.)
Safari Zone
Psyduck: 1 SpA - 5%
Doduo: 1 Atk - 60%
Mt. Pyre Interior
Shuppet: 1 Atk - 100% (Note: Shuppet can be found on Route 121 and 123 at 60%, and the outside of Mt. Pyre also at 60%).
Spear Pillar
Ariados: 2 Atk - 35%
Route 103
Poochyena: 1 Atk - 35% (Note: Poochyena can be found on Route 101 at 5%).
Route 102
Ralts: 1 SpA - 5%
Route 113
Spinda: 1 SpA - 95%
Route 117
Roselia: 2 SpA - 35%
I Hope I Helped!
EV Yields in Gen 6 (Source 1)
ORAS Horde Encounters (Source 2)
