Who is the killer of the grudge?

The killer in "The Grudge" is a vengeful spirit named Kayako Saeki. Her tragic backstory involves being murdered by her husband, which causes her spirit to become malevolent and curse anyone who enters her home. The curse manifests through terrifying supernatural occurrences, leading to the deaths of those who come into contact with her. The film explores the cycle of violence and Horror stemming from her unresolved rage.