Mozilla Firefox has a lot of security add-ons in the form of plugins. One such powerful OSINT plugin is Passive Recon. As the name suggests, this tool does not query the domain directly. In fact it looks up all the public databases for gathering as much information as possible about the target. Passive Recon passively provides whois information, MX records, DNS information, and other useful data. Significantly, due to the passive nature of Passive Recon, the owner of the domain you are querying is not alerted.