Script hostmap-crtsh

Script types: hostrule
Categories: external, discovery

Script Summary

Finds subdomains of a web server by querying Google's Certificate Transparency logs database (

The script will run against any target that has a name, either specified on the command line or obtained via reverse-DNS.

NSE implementation of ( by Sheila Berta.



Script Arguments


If set, add the new hostnames to the scanning queue. This the names presumably resolve to the same IP address as the original target, this is only useful for services such as HTTP that can change their behavior based on hostname.


If set, saves the output for each host in a file called "<prefix><target>". The file contains one entry per line.


See the documentation for the slaxml library., http.max-body-size, http.max-cache-size, http.max-pipeline, http.pipeline, http.truncated-ok, http.useragent

See the documentation for the http library.


See the documentation for the target library.

smbdomain, smbhash, smbnoguest, smbpassword, smbtype, smbusername

See the documentation for the smbauth library.

Example Usage

  • nmap --script hostmap-crtsh --script-args 'hostmap-crtsh.prefix=hostmap-' <targets>
  • nmap -sn --script hostmap-crtsh <target>

Script Output

Host script results:
| hostmap-crtsh:
|   subdomains:
|_  filename:



  • Paulino Calderon <>

License: Same as Nmap--See