Surah Al-Baqarah, Verse 12

أَلَآ إِنَّهُمۡ هُمُ ٱلۡمُفۡسِدُونَ وَلَٰكِن لَّا يَشۡعُرُونَ١٢

alā innahum humu l-muf'sidūna walākin lā yashʿurūna

Unquestionably, it is they who are the corrupters, but they perceive [it] not.