If you are looking to do more persisted research around a domain or ip address, consider checking out PassiveTotal (https://www.passivetotal.org https://www.pas

If you are looking to do more persisted research around a domain or ip address, consider checking out PassiveTotal (https://www.passivetotal.org https://www.passivetotal.org) . We draw in a lot of the same free feeds, but also have the most comprehensive passive dns aggregation out there, and let users pivot on Whois and ssl certificate data from Internet scans. API is documented and available to use for all account types. We also host free Maltego transforms if you want more of a graph analysis solution.