This dataset contains the responses to DNS requests for all forward DNS names known by Rapid7's Project Sonar. Until early November 2017, all of these were for the 'ANY' record with a fallback A and AAAA request if necessary. After that, the ANY study represents only the responses to ANY requests, and dedicated studies were created for the A, AAAA, CNAME and TXT record lookups with appropriately named files.
The data is updated every month. Historic data can be downloaded after creating a free account.