Ncat for Fun and Profit - The network Swiss army knife ... not so much.

Ncat was born out of the Google Summer of Code project and was written in similitude to Netcat by Hobbit but not using any of Hobbit's source code. 

There are some differences between Ncat and Netcat such as the omission of port scanning functionality - Ncat cannot take a list of ports to connect to on a host system, only a single port at a time, and has no port randomization or zero-I/O mode functionality. 

From the developers standpoint, this does make sense as it is bundled with the best port scanner in the world, Nmap. 

However, Ncat can't really take on the mantle of "The network Swiss army knife" by reducing functionality.

You can download the current stable and beta versions of Ncat from: Fyodor's Nmap site

The windows binary can be gotten in the Nmap Win32 zip distribution or installed as part of the Nmap installation using the windows installer version.

Here are some usage examples to try out for fun on your "lab network" (grin, grin, wink, wink)

Connect to nsa.gov on TCP port 8080.

• ncat nsa.gov 8080

Listen for connections on TCP port 8080.

• ncat -l 8080

Redirect TCP port 8080 on the local machine to host on port 80.

• ncat --sh-exec "ncat nsa.gov 80" -l 8080 --keep-open

Bind to TCP port 8081 and attach /bin/bash for the world to access freely.

• ncat --exec "/bin/bash" -l 8081 --keep-open

Bind a shell to TCP port 8081, limit access to hosts on a local network, and limit the maximum number of simultaneous connections to 3.

• ncat --exec "/bin/bash" --max-conns 3 --allow 192.168.0.0/24 -l 8081 --keep-open

Connect to smtphost:25 through a SOCKS4 server on port 1080.

• ncat --proxy socks4host --proxy-type socks4 --proxy-auth user smtphost 25

Create an HTTP proxy server on localhost port 8888.

• ncat -l --proxy-type http localhost 8888

Send a file over TCP port 9899 from host2 (client) to host1 (server).

• HOST1$ ncat -l 9899 > outputfile 
• HOST2$ ncat HOST1 9899 < inputfile

Transfer in the other direction, turning Ncat into a “one file” server. 

• HOST1$ ncat -l 9899 < inputfile 
• HOST2$ ncat HOST1 9899 > outputfile  

Hackers of the World - Unite!