Nafil after Qunut -ul- Witar
Hadrat Umm Salama (Radi Allahu Ta’ala Anha) narrated that the Prophet used to perform two Rakaats after Witar Salaah. Hadrat Aishah (Radi Allahu Ta’ala Anhu) and Hadrat Abu Umama (Radi Allahu Ta’ala Anha) have also narrated a similar tradition. [Ma’rif - ul- Hadis]
After Witar Salaah, the Prophet used to offer two simple rakahs of Salaah and used to recite surah al Zalzal (XCIX) and surah al-Kafirun (CIX). [lbn Majah]