The Umbrella Security Service (Special Forces Unit) (USS or USFU) were first introduced in Resident Evil 2. USS Alpha team attempted to steal a sample of the G-virus, causing the city-wide outbreak in the game. Delta team appeared in the prequel Resident Evil Zero; Delta team was sent in to blow up the Ecliptic Express after the trouble occurred, but was overwhelmed by the leeches and wiped out. D
elta team was under the direct command of Wesker and Birkin. Other games give further background for the Umbrella Special Forces. According to Code: Veronica, USFU agents are trained at the Rockfort Island facility. One of the more notable members of the USFU, HUNK, appears first in a minigame in Resident Evil 2, where he is given the mission of retrieving the G-virus from the research facility under Raccoon City. Canonically, he is the only survivor of his squad's mission. USFU agents are always depicted in solid-color grey fatigues, wearing protective vests and gas masks (except in Resident Evil: Apocalypse, where they are depicted in solid black fatigues, vests, and a type of enclosed helmet). They report directly to the highest ranking officers in Umbrella. Unlike the UBCS which performs more visible missions such as rescuing civilians, this unit maintains total secrecy and a small size. Also unlike the UBCS, this unit's personnel are not considered to be expendable. Members of the USFU are ex-military, highly trained, and dedicated to protecting Umbrella's various assets.