The coming of Dajjal is one of the biggest signs of the end - Day Of Judgement (Qayamat). The biggest fitnah for all mankind. Our beloved Holy Prophet Muhammad (ﷺ) had said,
"Between the time of the creation of Adam and the Resurrection Day, there is nothing greater than the mischief of Dajjal (the Antichrist)." ( Riyad as-Salihin : 1814 )
What to Recite for protection from Dajjal?
Prophet (ﷺ) said: "Whoever recites three Ayat from the beginning of Al-Kahf he is protected from the turmoil of the Dajjal." ( Tirmidhi: 2886 )
Abu Darda' reported Allah's Apostle (ﷺ) said: "If anyone learns by heart the first ten verses of the Surah al-Kahf, he will be protected from the Dajjal." ( Muslim : 809a )
In another narration, the Messenger of Allah (ﷺ) said: "(Whoever commits to memory) the last ten Ayat of Surat Al-Kahf, he will be protected from (the trial of) Ad-Dajjal (Antichrist)." ( Riyad as-Salihin 1021 )