Swiss Army Knife of Hacking/Networking Tool

Netcat

Vishal

About me

Vishal Patel

Enthusiast@InfoSec

Part Time Bug Hunter

Student @GFSU

What Is Netcat?

• Netcat—like so many hacker tools—was created to be a network analysis tool.
• Developed by a fellow only known as "Hobbit," he gave away this tool to the IT community without compensation, but has received scores of accolades. Thanks, Hobbit!
• As such, you can use it to open up TCP and UDP connections between two machines over any port your heart desires.

It can be used as,

• port scanning tool, similar to nmap
• leaving an open backdoor for the hacker
• Banner grabbing
• Raw connections
• Webserver interaction
• File transfers.

Netcat commands

• Open kali linux
• nc –h
•  As you can see, the basic syntax for netcat is the following.
• To connect to another machine: nc options host IP address port or nc [ip address][port]
• To listen for inbound connections: nc -l -p port

Netcat raw connection

• Once we have a TCP connection to a web server, we can use netcat to grab the banner of the web server to identify what web serving software the victim is running.
• Banner grabbing is a technique to retrieve this information about a particular service on an open port and can be used during a penetration test for performing a vulnerability assessment.
• Service banners are often used by system administrators for inventory taking of systems and services on the network.
• The service banners identify the running service and often the version number too
• Bullet Three

Web server interaction

•  Netcat can also be used to interact with webservers by issuing HTTP requests. With the following .command we can grab the banner of the web service running on Kali Linux
• Nc [ip of Target] [port: 80]
• HEAD / HTTP/1.0

Banner Grabbing

Port Scan

• > nc –nvz ip of Target machine 1-100
•  If you find open port and wants to connect
• > nc Host/Target ip port
• By default it scans the TCP ports. For UDP, you can use  > nc -nvz -u ip port

File Trasnfering

• If you Want to  Transfer the File/Script then you can use it like,

• In Computer A type : >

• cat somethin | nc -l -p [port]//At the receiving end  

• In Computer B type :>

•  nc ip.Reciver [port] >  somethin   //At the sending end

Text Transfering/Chat

• If you Want to  share message/chat  then you can use it like,
• In Computer A type : > nc -l -p [port] //At the receiving end  

• In Computer B type :>

•  nc ip.Reciver [port] //At the sending end

• Happy chatting! :)

Thank you!!