Collecting valid e-mail accounts and IP addresses from web servers

Valid e-mail accounts are useful in penetration testing engagements because they can be used for exploiting trust relationships in phishing attacks, password auditing of mail servers, and as usernames in many IT systems including Active Directory services.

This recipe illustrates how to get a list of valid public e-mail accounts with Nmap.

How to do it...

Open your terminal and enter the following command:

# nmap -p <Port> --script http-grep <target>

 

Nmap will crawl the web application and return any interesting information found, as follows:

# nmap -p443 --script http-grep nmap.org  
   Nmap scan report for nmap.org (45.33.49.119) 
   Host is up, received syn-ack (0.072s latency). 
   Other addresses for nmap.org (not scanned):     
   2600:3c01::f03c:91ff:fe98:ff4e 
   rDNS record for 45.33.49.119: ack.nmap.org 
   Scanned at 2016-08-22 10:44:08 CDT for 9s 
   PORT    STATE SERVICE REASON 
   443/tcp open  https...