On the authority of Abu Abdurahmaan Abdullah, the son of Umar ibn Al-Khattab (ra), who said: I heard the Messenger of Allah, Muhammed (saw) say: Islam has been built on five [pillars]: testifying that there is no deity worthy of worship except Allah and that Muhammad is the Messenger of Allah, establishing the Salaah (prayer), paying the Zakah (obligatory charity), making the Hajj (pilgrimage) to the House, and fasting in Ramadan.

(Sahih Bukhari and Muslim)

We are told that if we suspect anything like sihr (witchcraft) or jinn, then Ayatul Kursi and the 3 Quls suffice from all harm and mischief.