Allah's Apostle (ﷺ) as saying: If anyone learns by heart the first ten verses of the Surah al-Kahf, he will be protected from the Dajjal.
Source: Muslim: 809
Duas from IslamicAPI's Masnun Dua dataset (based on the Quran, hadith, Hisnul Muslim and Rahe Belayat). See the dataset