It is narrated from Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "Allah has never sent any Prophet, nor appointed anyone to the office of caliph, except that he has two kinds of close, confidential advisers: one group that urges him to do good and forbids him from evil, and another group that spares no effort in ruining and corrupting him. So whoever is protected from the evil of bad advisers has indeed been protected (from all evil)."
Hadith Referenceالمعجم الأوسط / باب العين / 4612
Hadith Takhrij«أخرجه البخاري فى «صحيحه» برقم: 6611، 7198، وابن حبان فى «صحيحه» برقم: 6192، والنسائي فى «المجتبى» برقم: 4213 / 2، والنسائي فى «السنن الكبرى» برقم: 7777، 8702، والبيهقي فى «السنن الكبرى» برقم: 20374، 20373، 20372، وأحمد فى «مسنده» برقم: 11517، 12014، وأبو يعلى فى «مسنده» برقم: 1228، والطحاوي فى «شرح مشكل الآثار» برقم: 2113، 2114، 2115»