The commandos are an elite special forces unit privately owned by the Weyland-Yutani Corporation.
The commandos made their debut during their brief appearance in the climax of Alien 3. They escorted a group of Weyland-Yutani researchers that were led by Michael Bishop on Fiorina 161 with the intentions of retrieving the Xenomorph Queen embryo within Ellen Ripley. The commandos killed Francis Aaron for assaulting Michael and takes the last surviving prisoner, Robert Morse into custody for relocation after Ripley had committed suicide to prevent the company from getting the Queen embryo.
In Aliens vs Predator 3, combat androids wearing similar armor are seen. They bleed white synthetic fluid, their faces resemble a human skull crudely laced with white synthetic muscle with their pupils being the Weyland-Yutani logo. They are extremely durable and are capable of withstanding damage that would kill a normal human Marine. They are equipped with captured Predator technology, using personal camouflage generators.
Weyland-Yutani commandos are clad in full-body armor with a backpack and a helmet that protects the face dubbed as "apesuits." In theory this heavy armor is designed to protect the soldier from the powerful melee attacks and acid blood of Xenomorphs but their capabilities are never shown/tested in the film.
In Alien 3 , Weyland-Yutani commandos are armed with the M41A Pulse Rifle. In Aliens vs Predator 2010, Weyland-Yutani combat androids are armed with the ZX-76 Shotgun, the M42C Sniper Rifle and the M41A Pulse Rifle.