كتاب الْمَسَاجِدِ وَمَوَاضِعِ الصَّلاَةِ
5  
The Book of Mosques and Places of Prayer
(54)
Chapter: It is recommended to say qunut in all prayers if a calamity befalls the Muslims – and refuge is sought from Allah (regarding that). It is recommended to say qunut in Subh at all times. And the clarification that it is to be said after raising the head from bowing in the final rak`ah, and it is recommended to say it out loud
(54)
باب اسْتِحْبَابِ الْقُنُوتِ فِي جَمِيعِ الصَّلاَةِ إِذَا نزَلَتْ بِالْمُسْلِمِينَ نَازِلَةٌ ‏‏
Sahih Muslim 677 i

A hadith like this has been transmitted by Anas from the Messenger of Allah (way peace be upon him).

وَحَدَّثَنَا عَمْرٌو النَّاقِدُ، حَدَّثَنَا الأَسْوَدُ بْنُ عَامِرٍ، أَخْبَرَنَا شُعْبَةُ، عَنْ مُوسَى بْنِ أَنَسٍ، عَنْ أَنَسٍ، عَنِ النَّبِيِّ صلى الله عليه وسلم بِنَحْوِهِ ‏.‏
Reference : Sahih Muslim 677i
In-book reference : Book 5, Hadith 386
USC-MSA web (English) reference : Book 4, Hadith 1441
  (deprecated numbering scheme)