Movie where a man has an alien growth on his arm [duplicate]

Question

I only remember part of this horror movie. In it, a group of characters, including a man and a woman, are at what I think was a gas station at night? The man has some kind of alien infection on his arm, and the woman remarks that this alien thing is either growing or spreading. The other characters decide to cut off his arm right there and then to stop its spread.

Answer 1

Might this be Splinter (2008)...?

From Wikipedia:

The film opens on a sleepy gas station, where the pump attendant is attacked by a splinter-infected animal. The attendant's body begins to contort. A young couple, Seth Belzer (Paulo Costanzo) and Polly Watt (Jill Wagner), drive for a romantic camping trip in the forests of Oklahoma, but their plans are shattered when they are car-jacked by an escaped convict, Dennis Farell (Shea Whigham), and his drug-addict girlfriend, Lacey Belisle. The group gets a flat tire when they run over a splinter-infected animal on the road. They find shelter at the now-abandoned gas station.

Lacey discovers the horribly-infected pump attendant, writhing in the bathroom. She is attacked and is killed by the monster, but her corpse slowly reanimates and becomes a new creature, which attacks the remaining survivors. While fighting her, Seth, Polly and Dennis discover that severed pieces of the infected victims are capable of attacking on their own. Sheriff Terry Frankel arrives and attempts to arrest Dennis, but is ripped in half by Lacey's corpse. The creature takes the top half of the officer's body and bonds with it, becoming a larger creature. The trio hide in the walk-in refrigerator when a piece of the creature's arm attacks them. It is discovered that Dennis has been infected, as his left arm violently twists on its own. Seth and Polly amputate his arm to prevent the infection from spreading. Dennis explains that he had been pricked by a splinter from the dead creature they encountered on the road. Seth discovers that the creatures themselves are actually a fungus taking control of the corpses they infect and consuming the blood in the body, using the currently zombified host to seek out fresh and new hosts. Because of this, they hunt based on temperature; attacking the warmest thing they can find.