The correct answer is theHarvester. It is specifically designed to gather publicly available information such as email accounts, subdomain names, virtual hosts, open ports, and banners from different public sources like search engines and PGP key servers. This makes it suitable for passive reconnaissance. Nmap is typically employed for active scanning and could inadvertently set off security alarms if used inappropriately. SQLmap is an automatic SQL injection and database takeover tool, which is not intended for initial reconnaissance. CeWL creates custom wordlists from a given URL, useful for creating targeted password lists, but does not serve the purpose of identifying services and devices.