This prayer to Saint Michael the Archangel was endorsed by Pope Leo XIII in 1886. From 1886 to 1964 (implementation of changes of Vatican II), this prayer was recited after Mass in the Catholic Church; and has enjoyed somewhat of a revival in many churches today.
St. Michael the Archangel, defend us in battle, be our protection against the wickedness and snares of the devil. May God rebuke him we humbly pray; and do thou, O Prince of the Heavenly host, by the power of God, cast into hell Satan and all the evil spirits who prowl about the world seeking the ruin of souls.
Read more about Saint Michael the Archangel at https://churchwonders.com/mary-saints/saints/saint-michael-the-archangel/