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