Pray to Lord Narasimha for protection by chanting the Narasimha Kavacha Stotra. This is a prayer from the Brahmanda Purana, formerly spoken by Prahlada Maharaja. It is said that one who chants this mantra is bestowed with all opulence and can be elevated to the heavenly planets. One should first meditate on the transcendental form of Lord Narasimha (as described in verses 3 to 6 of Narasimha Kavacha Stotra) and pray to Him for our protection.

It is said that the Narasimha Kavacha Stotra is the king of all mantras. One who chants this becomes free from all sins. It removes all evil influences in the family and drives away the ghostly disturbances. Whatever one desires in this world can be definitely attained if one chants this mantra regularly as per the procedure with a pure heart. All the diseases (especially those of abdomen) will vanish and he will achieve victory in all his endeavors.
Sri Narasimha Kavacha Mantra
narasimha-kavacaṁ vakṣye prahlādenoditaṁ purā sarva-rakṣā-karaṁ puṇyaṁ sarvopadrava-nāśanam
sarva-sampat-karaṁ caiva svarga-mokṣa-pradāyakam dhyātvā nṛsiṁhaṁ deveśaṁ hema-siṁhāsana-sthitam
vivṛtāsyaṁ tri-nayanaṁ śarad-indu-sama-prabham lakṣmyāliṅgita-vāmāṅgam vibhūtibhir upāśritam
catur-bhujaṁ komalāṅgaṁ svarṇa-kuṇḍala-śobhitam śriyāsu-śobhitoraskaṁ ratna-keyūra-mudritam
tapta-kāncana-sankāśaṁ pīta-nirmala-vāsasam indrādi-sura-mauliṣṭha