By Allah, I am the closest of you in prayer to the Messenger of Allah ﷺ. Abu Hurairah used to recite the qunut in the final rakah of the night prayer and the dawn prayer, after saying, "Allah hears the one who praises Him." He would supplicate for the believers and invoke curses upon the disbelievers.
حدثنا عبد الصمد حدثنا هشام عن يحيى عن أبي سلمة
والله إني لأقربكم صلاة برسول الله وكان أبو هريرة يقنت في الركعة الآخرة من صلاة العشاء الآخرة وصلاة الصبح بعدما يقول سمع الله لمن حمده فيدعو للمؤمنين ويلعن الكفار
Its isnad is sahih. The place of the qunut is after the ruku, and something similar has been narrated from Abu Hurairah, that the Messenger of Allah ﷺ, whenever he wanted to pray against someone or pray for someone, would recite the qunut after the ruku. Sometimes, when he said, "Allah hears whoever praises Him, our Lord, to You belongs all praise," he would say, "O Allah, save Walid bin Walid, Salama bin Hisham, and Ayyash bin Abu Rabia, and the oppressed among the believers. O Allah, tighten Your grip upon Mudar and make it years like the years of Yusuf," saying this aloud. And in some of his prayers during the Fajr prayer he would say, "O Allah, curse so-and-so and so-and-so," naming certain tribes among the tribes of the Arabs. So Allah revealed,"You have no say in the matter, whether He turns to them in mercy or punishes them, for indeed they are wrongdoers" [Al Imran 3:128].It was narrated by Darimi, the two Shaykhs, Abu Dawud, and Bayhaqi, with similar wordings.