Assalaamu alaykum. Are the reports in Al-Fitan by Nu'aim ibn Hammad authentic?

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger. 

Not all the ahaadeeth cited in Al-Fitan by Nu‘aym ibn Hammaad are authentic; rather, the book included inauthentic ahaadeeth and even fabricated reports. In fact, the author, Nu‘aym ibn Hammaad, himself was declared a weak reporter by scholars.

One of these fabricated reports cited in the book is the following:

“When there is a Sayhah (loud cry) in Ramadhaan, then there will be turmoil in Shawwaal, and the tribes will form groups in Thul-Qa‘dah, and blood will be spilled in Thul-Hijjah and in Al-Muharram! And what Al-Muharram!” saying it three times, “Oh, Oh! The people will be killed in great massacres.” People said, “What is the Sayhah, O Messenger of Allah?” He replied, “A thud in the middle of Ramadhaan, on a Friday eve, that will awaken one who is asleep and bring the young women out of their rooms, on a Friday eve during a year of many earthquakes. So when you have prayed the Fajr on Friday (in the middle of Ramadhaan), then enter your houses, close your doors, block your windows, cover yourselves, and block your ears. When you sense the loud cry, fall down in prostration to Allah and say, ‘Subhaan Al-Quddoos, Subhaan Al-Quddoos, Rabbuna Al-Quddoos’ (which means: Glory be to the Most Holy, glory be to the Most Holy, our Lord is the Most Holy), for whoever does that will survive, and whoever does not do so will perish.”

Al-Albaani judged this report to be fabricated.

Allah knows best.