Alien Abduction

Jean and her three friends are on a camping trip in the mountains when they are targeted from space. Jean is the first to notice something wrong when she video tapes a UFO flying overhead. At first her friends don't believe her and they are not convinced from what they see on the tape. But that night when they are sitting around the camp fire with Jean taping their antics, the Aliens attack. The four friends flee for their lives, Jean still clutching the camera, but there is no way to escape. Eventually they are netted and transported from the earth's surface. Jean and her friend's wake up in a holding cell on the ship. Jean uses the camera's night vision to explore the alien glyphs and passages. Then a horrific alien vocalization comes over a loud speaker and the friends are rounded up and pushed into a room where they are tied up and vivisected.Jean awakens in a hospital suffering from terrible flashbacks, flashbacks of her violent abduction. Then, in the night, alone and in the dark, a shadowy figure comes into her room and staples something into the back of her neck. The flashbacks stop. Jean has no memory of the abduction.Jean is questioned by a staff psychiatrist, Dr. Booker, who reveals that she is in a specialized hospital for those who have been abducted by UFOs. She has to remain under their care until they are certain that she can return to her regular life without causing a panic. The military attache, commander Shakti is not so generous with Jean. She wants her locked up and lobotomized. Jean only adds to her desperate situation by breaking into a private wing of the hospital to find one of her friends who she sees going in there. To her horror that part of the hospital is reserved for mutants, the insane and people who are being lobotomized. Jean is captured by Shakti and given electric shock until she is unconscious. When She wakes up, Shakti interrogates her and then sends her to her death in an execution room. But Jean knocks out the medical technician and escapes into the waste system. She wanders underneath the facility looking through vents for a way out. Until she finds a storage room with nobody in it. She crawls out and explores, eventually finding her own things in a box with her name on it. In there is her video camera. The tape is gone but the memory stick is still there. She replays the video and is shocked to see the entire abduction on tape. She quickly escapes from the storage room killing a guard on the way. She also sees and tapes a scientist tending to and maybe even breeding alien larvas in a secret lab.Jean breaks into a medical technicians locker room and disguises herself from head to toe. She overhears that the aliens have escaped form the lab and are infecting the facility. So the conflict with the Aliens is escalating and the hard-liners must purge the facility of those that they believe to be spies and traitors.One by one the infected people are killed only to reveal an alien larva cracking out of their faces and escaping. Jean tries to save her friends from the secret wing but they are a mess and Todd barely seems to remember that he even knows her. Jean gets them to near safety when Todd turns on them.The final moments of the film cannot be revealed a this time (some reviews have said that this film has one of the best endings of all time).

Question: Jean and her friends are attacked by what?
Answer: Aliens