How to use Netcat: Commands and use cases

<p>Netcat is arguably the most flexible network security tool available to security administrators today, and one that is valuable for any security practitioner to have in-depth knowledge of.</p>
<p>Let’s take a look at how to use Netcat and explore some situations where you can put it to good use.</p>
<section class=”section main-article-chapter” data-menu-title=”Netcat: Security’s Swiss Army knife”>
<h2 class=”section-title”><i class=”icon” data-icon=”1″></i>Netcat: Security’s Swiss Army knife</h2>
<p><a target=”_blank” href=”https://nc110.sourceforge.io/” rel=”noopener”>Netcat</a> is a small, lightweight tool designed to send and receive data over a network. Much like the Linux and Unix cat utilities output the content of a file to a terminal or stdout, Netcat does the same thing but over the network.</p>
<p>While this sounds modest in scope, security practitioners can use it creatively and string it together with itself or other commands in surprisingly powerful ways. Consider just a few of the many possible use cases:</p>
<ul class=”default-list”>
<li><b>Penetration testers.</b> Netcat can serve as a testing harness for interacting directly with a listening (server) socket or even as a quick-and-dirty command-and-control interface — e.g., <a href=”https://www.techtarget.com/searchsecurity/tip/What-reverse-shell-attacks-are-and-how-to-prevent-them”>reverse shell</a>.</li>
<li><b>Application security specialists.</b> Netcat can connect to APIs, test and interact with proprietary protocols at a low (i.e., socket) level, and help gather information during reconnaissance.</li>
<li><b>Network engineers.</b> Netcat is a simple and effective tool to test connectivity between different endpoints.</li>
<li><b>Students.</b> Netcat is an excellent way to learn networking fundamentals and experiment with network communications.</li>
</ul>
<p>The widespread popularity of Netcat boils down to the following key factors:</p>
<ul class=”default-list”>
<li><b>Ubiquity.</b> Many Linux distributions — whether security-focused or general-purpose –include Netcat by default.</li>
<li><b>Portable.</b> If a platform has a shell and a network connection, chances are good you can

[…]
Content was cut in order to protect the source.Please visit the source for the rest of the article.