All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Every Muslim is to believe firmly that no one, however great his powers may be, can benefit or harm him unless Allah wills it. Then a Muslim’s best protection and immunity against black magic is by practicing Islam, reading the Qur’an and making frequent dhikr and du`a’.
“Your best protection and immunity against black magic is by empowering yourself through practicing Islam, reading the Qur’an and making constant dhikrand du`a’.
Allah has promised the faithful that devils cannot exercise permanent control over those servants of Allah who have submitted to Him; Satan can exercise permanent control only over those who acquiesce and surrender themselves to his authority. Almighty Allah says: “Most certainly, My servants–you cannot exercise control over them except those who are deviant who follow you.” (Al-Hijr: 42) “Most certainly he (Satan) has no power over those who truly cherish faith and are trusting upon their Lord; rather his power is limited only to those who take him as a protector (besides God) and thus associate partners with Him.” (An-Nahl: 99-100)
The first and foremost requirement is to believe firmly that no one, however great his powers may be, can benefit or harm you except if Allah wills it. The Qur’an reminds us repeatedly that a true believer must believe firmly that Allah alone is the One Who can give us benefit or harm in an absolute sense; everything that befalls us from humans or other creatures is only secondary and is achieved only through the power derived from Allah; so the best remedy and cure is to continuously seek protection and refuge in Allah. Satan and all of his tricks and weapons could be defeated and rendered utterly ineffective if Allah wills.
Duas that protect from black magic:
2) Last three chapters of the Qur’an (i.e., Surahs 112, 113, 114)
3) Ayat al-Kursi (i.e., Al-Baqarah: 255)
Besides the above, repeat the following du`a’s on a regular basis both in the morning and evening three times or more:
1) Bismillahi alladhi la yadurru ma`a ismihi shay’un fi al-ardi wa la fi as-sama’i wa huwa as-sami`u al-`alim
(In the name of Allah; with His name, nothing whatsoever on earth or heaven can inflict any harm; He is All-Hearing and All-Knowing).
2) Hasbiya Allahu la ilaha illa huwa `alayhi tawakkaltu wahuwa rabbu al-`arshi al-`azhim
(Allah suffices me; there is no god but He; in Him I place my sole trust; He is the Lord of the mighty Throne).
3) Allaahumma ini a`duhu bika min hamazati ash-shayatin wa a`udhu bika rabbi an yahdurun
(O Allah, I seek refuge in You from the whisperings of Satan; my Lord, I seek refuge in You from their presence around me).
4) A`udhu bi `izzati Allahi wa qudratihi mimma ajidu wa uhadhiru
(I seek refuge in Allah’s glory and power from the affliction and pain I experience and suffer from).
It is important to remember that du`a’ and dhikr will only benefit when it comes from a heart that firmly believes in Allah, and thus cherishes firm conviction in Allah’s power and sovereignty.”
Allah Almighty knows best