Abu Dawud Book 30, Hadith Number 4231.

Narated By Hudhayfah ibn al-Yaman : I swear by Allah, I do not know whether my companions have forgotten or have pretended to forgot. I swear by Allah that the Apostle of Allah (PBUH) did not omit a leader of a wrong belief (fitnah) – up to the end of the world–whose followers reach the number of three hundred and upwards but he mentioned to us his name, his father’s name and the name of his tribe.