Hide and Go Kill (2008)

A blog on a mysterious website quickly spreads like wildfire, starting a dangerous online game. At 3:00 in the afternoon, a teddy bear stuffed with rice and nails is sunk into a bathtub. The lights go out and the player is required to stab the bear with the knife, then write their experiences in the blog. But lately the comments have taken a dark, demented turn, as if the players are being possessed.

Unfortunately the movie Hide and Go Kill is not yet available on HBO Max.