Using Nmap, the network scanner ~ DepoTech

Nmap is an open source port scanner that allows the exploration network and get information about the operating system of a remote computer, this software is increasingly used by network administrators as the audit of the results of Nmap provides precise indications of a network. It is available on Linux, Windows and Mac OS.

In this article we will describe the basic operation of Nmap Backtrack Linux 5 and identify key points of your servers or machines to avoid Imprévu attacks.

Use:

Identify the operating system of a remote machine

nmap -O 127.0.0.1
If nmap can not identify the version of your OS, you can view a list of systems that could potentially match:

nmap -O---osscan guess 127.0.0.1

Detecting machines on a network

If you want to identify all existing machines on your network.

nmap 192.168.0.0/10 -sP
View open ports on a machine
A port scan allows you to see how your machine is seen from the outside, what are the services that are available. As against a port scan allows a hacker to see the services running away to find a flaw on one of these services and how it can go further in the attack.

nmap 127.0.0.1
Scanner for a specific port. Here is the HTTP port:

nmap -p 80

Spoof the MAC address

The MAC address spoofing is change a MAC address so that it resembles that of another network card. This technique is called "MAC Spoofing"

--spoof nmap-mac 01: 02: 03: 04: 05: 06 127.0.0.1
--spoof nmap-mac Cisco 127.0.0.1

View all open TCP ports

nmap 127.0.0.1 -sS 80

View all UDP ports

nmap 127.0.0.1 -sP 80

Scan ftp bounce

The FTP bounce scan (FTP Bounce) is ensured by the -b option, it can ask the FTP server to port scan for you. This technique is a little old but it is still possible to find vulnerable FTP servers.

In my case I go through my local ftp server that has the address 127.0.0.1 to scan an IP address range:

nmap -b 127.0.0.1 192.168.0, .0-255
The real utility of Nmap for hackers is in the combination of the latter with Metasploit Framework to scan one or more machines and automatically launch exploits. : D

That's why I encourage you to test Nmap on your network to verify that your machines have no exploitable flaw.

If you have other examples of uses, you can post a comment.

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