There are several Greek goddesses who could be considered bringers of misfortune, depending on the specific type of misfortune:
Eris: Goddess of discord, strife, and rivalry. She incited the Trojan War by throwing a golden apple inscribed "To the fairest" among the goddesses Hera, Athena, and Aphrodite.
Keres: Violent death personified. Keres are often depicted as frightening figures who carry away the dead.
The Erinyes (also called Furies): Avenging goddesses who pursued those who committed crimes like murder and perjury.
Hekate: Goddess of magic, witchcraft, crossroads, and ghosts. While not inherently evil, she was associated with the underworld and the darker aspects of life.