Islam prohibits backbiting and slandering.
"Backbiting and Gossiping are from the most vilest and despicable of things, yet the most widely spread amongst mankind, such that no one is free from it except for a few people." Backbiting (gheebah) means mentioning something about a person (in his absence), that he hates (to have mentioned), whether it is about: His body, his religious characteristics, his worldly affairs, his self, his physical appearance, his character, his wealth, his child, his father, his wife, his manner of walking, hi