Dead Sign (2013)

When art student Kangsheng returns to his remote hometown village with his classmates to search of ancient murals, they are witness to a fatal car accident. Kangsheng's girlfriend Wangzhi unintentionally interrupts the local witchcraft ritual for the deceased. Horrified, the group flee the scene and settle at the inn owned by Kangsheng's mother. The following day, out searching for murals, the group find instead a mysterious hand-painted sign in a cave. The surprises are only beginning.

Unfortunately the movie Dead Sign is not yet available on HBO Max.