Cemetery Wind was a secret black operations unit of the Central Intelligence Agency created by Harold Attinger (the main antagonist) in Transformers: Age of Extinction and they were the main antagonistic group in the movie.
Cemetery Wind was formed after the battle of Chicago and the disbandment of NEST as the human alliance with the Autobots had been terminated. They were tasked to eliminate any remaining Decepticons on Earth and was ordered by the President to leave the Autobots alone, but Attinger secretly disobeyed the President; he took advantage of his authority, made a deal with Lockdown, eliminating all Transformers, delivering their remains to KSI to melt them down for materials to build their artificial, remote-controlled Transformers, make them a better world and killing anyone who found out of their operation. Decided to function as a state police, they started offering financial rewards to ordinary citizens that report alien activity towards them.
Targeting the Autobots
They killed both Leadfoot and Ratchet before proceeding to do the same with Optimus Prime. An off-screen battle explained by Lockdown was that Cemetery Wind and Lockdown were fighting him in Mexico City, having managed to shoot Optimus three times, yet he was still able to escape and fled the scene to avoid getting killed, causing Lockdown to start blaming and reconsider his contract with Cemetery Wind.
Attempting to target the Yeager family and a car chase in Texas
Cade Yeager's greedy, backstabbing friend Lucas Flannery turned Optimus in, but rather than getting the check, Lucas got guns pointed at his face when Cemetery Wind couldn't find Optimus and suspected Cade, Tessa and Lucas were all hiding the Autobot leader. Optimus refused to sacrifice Cade and Tessa's lives to further ensure his own safety, so he jumped out to attack Cemetery Wind, although he didn't have enough time to wipe them all out when Lockdown started chasing him. A chase erupted in the city with Cemetery Wind pursuing Cade, Tessa, Shane and Lucas. The humans successfully escaped by driving off a ramp and, except for Lucas who gets killed by Lockdown's grenade, manage to reconnect with Optimus to escape. Then, Attinger scolds and demerits his men for their failure to capture Optimus, not considering at all that the Autobot was too biologically advanced for human capture.
Conclusion and Disbandment
After the war in Hong Kong ended, and with both Attinger and Savoy's deaths, Cemetery Wind was disbanded by the President and the U.S. government and labeled as a hostile organization. It was presumed that the other Cemetery Wind members either have been killed or arrested for their actions, as they are now No. 1 on the NSA, CIA, Interpol and FBI's most wanted list.