Netcat will remain up and listening until it receives an end of file (EOF) delimiter. We start up netcat using the '-l' flag so that it is listening and the '-p' flag to specify what port we want. We have netcat installed on our local workstation and first we need to set up a listener to capture the incoming data. A simple example will probably serve to demonstrate the modes better.įor the purposes of our example let's say we wanted to 'export' the password file off of a remote Linux workstation. The two modes are distinct so you must understand how to use netcat before you get started. The client can be used to pipe data off the filesystem out over a port and the listener (or server) can open a port and listen for incoming data. The unix/linux version is available from SourceForge at but is also available with most Linux distributions. The windows version is available from at. Netcat is available for both windows and *unix systems. Additionally, netcat is an unauthenticated protocol, so it duplicates much of the ease of use that makes TFTP (trivial file transfer protocol) attractive. Moving files to and from hosts without another transport program, such as FPT, SSH or windows filesharing is incredibly useful. At first this seems fairly trivial, but it is extremely useful for transferring files in absence of other utilities. Netcat listens to traffic on a port and redirects that traffic to output (either standard output or even to a file). Netcat is, as it name suggests, a program utilized to concatenate network traffic. The fact that netcat is a favorite tool among malicious hackers does a great disservice to the tool, but it also demonstrates its utility. While many admins have heard of netcat, it is usually in the context of detecting rootkits or evidence of intrusion. Netcat is an oft maligned program that can easily be used for many interesting and useful purposes.

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