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Nmap 6: Network Exploration and Security Auditing Cookbook

Nmap 6: Network Exploration and Security Auditing Cookbook

4.7 (9)
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Nmap 6: Network Exploration and Security Auditing Cookbook

Nmap 6: Network Exploration and Security Auditing Cookbook

4.7 (9)

Overview of this book

Nmap is a well known security tool used by penetration testers and system administrators. The Nmap Scripting Engine (NSE) has added the possibility to perform additional tasks using the collected host information. Tasks like advanced fingerprinting and service discovery, information gathering, and detection of security vulnerabilities."Nmap 6: Network exploration and security auditing cookbook" will help you master Nmap and its scripting engine. You will learn how to use this tool to do a wide variety of practical tasks for pentesting and network monitoring. Finally, after harvesting the power of NSE, you will also learn how to write your own NSE scripts."Nmap 6: Network exploration and security auditing cookbook" is a book full of practical knowledge for every security consultant, administrator or enthusiast looking to master Nmap. The book overviews the most important port scanning and host discovery techniques supported by Nmap. You will learn how to detect mis-configurations in web, mail and database servers and also how to implement your own monitoring system. The book also covers tasks for reporting, scanning numerous hosts, vulnerability detection and exploitation, and its strongest aspect; information gathering.
Table of Contents (18 chapters)
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Nmap 6: Network Exploration and Security Auditing Cookbook
Credits
About the Author
Acknowledgement
About the Reviewers
www.PacktPub.com
Preface
References
Index

Detecting backdoor SMTP servers


Compromised servers might have rogue SMTP servers installed and abused by spammers. System administrators can use Nmap to help them monitor mail servers in their network.

This recipe shows how to detect rogue SMTP servers by using Nmap.

How to do it...

Open your terminal and enter the following Nmap command:

$ nmap -sV --script smtp-strangeport <target>

If a mail server is found on a non-standard port, it will be reported in the script output section:

PORT    STATE SERVICE  VERSION 
9999/tcp open  ssl/smtp Postfix smtpd 
|_smtp-strangeport: Mail server on unusual port: possible malware

How it works...

The script smtp-strangeport was submitted by Diman Todorov. It detects SMTP servers running on non-standard ports, which is an indicator of rogue mail servers. If an SMTP server is found running on a port other than 25, 465, and 587, this script will notify you.

The argument -sV --script smtp-strangeport makes Nmap start service detection and launch the NSE...

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