Is being wary of people and not trusting them until their trustworthiness is proven, without accusing them of ill intent, considered having ill thoughts (su' al-dhann)?

Being cautious of people one does not know is a matter of prudence and necessary precaution, and not a blameworthy suspicion in Islamic law. Abu Dawud dedicated a chapter in his Sunan to being cautious of people, and in it, he cited the Prophet's (peace be upon him) narration to Amr ibn al-Faghwa al-Khuza'i: "If you descend upon the land of his people, then be cautious of him." Al-Azhari mentioned that being cautious of people means not to trust everyone, as it is safer for a person.