以下是一些常用的子域名查询工具:
1. DNSdumpster: https://dnsdumpster.com/
2. Sublist3r: https://github.com/aboul3la/Sublist3r
3. Subfinder: https://github.com/projectdiscovery/subfinder
4. Amass: https://github.com/OWASP/Amass
5. Knockpy: https://github.com/guelfoweb/knock
6. Fierce: https://github.com/mschwager/fierce
7. Recon-ng: https://github.com/lanmaster53/recon-ng
8. TheHarvester: https://github.com/laramies/theHarvester
9. Shodan: https://www.shodan.io/
10. Censys: https://censys.io/