DNSGen
Intelligent DNS permutation tool for subdomain discovery
...These generated permutations help identify hidden or unlisted services that may not appear in standard DNS queries or public records. DNSGen applies multiple permutation techniques to create realistic domain combinations based on modern infrastructure naming patterns, including cloud environments, DevOps tools, and microservice architectures. It can also extract meaningful keywords from existing domain names and incorporate them into newly generated permutations. The resulting domain list can be further processed by DNS resolution tools such as MassDNS to determine which generated domains actually exist.