Here is the full list of all 27 Call of Duty: Modern Warfare achievements.
Complete 'Clean House' without being hit using one bullet per threat.
Kill an enemy with a direct hit from a smoke grenade.
Kill at least one enemy while inside The Reading Place, Aural Chic, and both Subway undergrounds.
Reach Barkov's lab entrance using only drone strikes.
Take down a flying helicopter with a molotov.
Kill all the enemies in the 'Embedded' field of dead bodies.
Shoot the driver of the suicide truck.
Complete every single player mission on Veteran or Realism difficulty.
Finish single player on any difficulty.
Kill all enemies at the Church, Clocktower, and Pool without anyone calling for backup.
Get at least one kill with eight different weapons when completing 'Old Comrades'.
Shut off the power to 4 buildings in 'Going Dark'.
Never get hit by the sniper while escaping captivity.
Spit on Barkov.
Kill 3 enemies while you are on a ladder.
Complete 'The Wolf's Den' tunnels using only the 1911.
Kill both soldiers with one shot in 'Hometown'.
Stop three APCs with Hadir's sniper rifle.
Destroy 4 trucks with 4 drone strikes before they reach the end of their path in 'The Embassy'.
Blow up 3 tripwires with explosives.
Save Alpha 3-2 from being downed.
Burn 4 enemies with a single molotov.
Crash a helicopter by shooting the pilot.
Only use one cinder block and bring it to the end of 'Embedded'.
Do not injure any civilians in 'Piccadilly'.
Neutralize the 'Fog of War' machine gun with a frag grenade.
Complete all Special Operations missions.