How to use Kali Linux: Over time, you are becoming an IT security enthusiast always ready to enrich your cultural background with new knowledge on the sector. Speaking with an IT expert friend, he, happy with your new direction, advised you to try Kali Linux to perform the first security tests on your network and on your personal files. Let me tell you: your friend couldn’t give you better advice! In fact, Kali Linux is a Linux distribution designed to test network security and for many other aspects of forensic computing (recovery of damaged files, recovery of data from corrupt disks and so on).
The problem, however, is that you don’t have the faintest idea of how to use Kali Linux and, this time, you have decided to ask Google for help, ending up right on this guide. Did I guess? All right, then this is just the right place from which you can start: below, I will explain in detail all there is to know about the use and functioning of Kali Linux. In detail, I will give you a complete overview of the versions of Kali available, I will explain what are the minimum requirements for installing the system, I will explain how to complete the latter and, finally, I will guide you in using the most important distro functionality.
Before starting, however, let me make an important clarification: accessing others’ wireless networks without permission represents a serious violation of privacy and, in some cases, it can even be a crime. I do not want in any way to encourage activities of this type and, therefore, I do not take any responsibility for the use that you will make of the indications given in this guide. Having said that, I have nothing else to do but wish you a good read and good work with Kali Linux!
As I have already explained to you in the introductory lines of this guide, Kali Linux is a distribution rich in pre-configured tools and software, dedicated to penetration testing and forensic informatics : it is a Debian- based distribution , available for both for computers based on 32/64 bit Intel processors and for ARM architecture based devices.
Although the “heart” of the operating system remains the same, Kali Linux can be downloaded both with the desktop environment (in different versions) and without. Below I list the available versions.
- Default – simply referred to as “Kali Linux”, it is based on the GNOME 3 desktop environment.
- LXDE – shares the entire software park, with the exception of the desktop environment, with the default version. It is based on the LXDE desktop, which is particularly light and suitable for machines with low graphics performance.
- Mate – this is the variant equipped with the intuitive Mate desktop.
- KDE – differs with other versions in the presence of the KDE Plasma environment, which can be customized at 360 degrees.
- E17 – has the Enlightenment environment in version 17 (E17), a modular desktop and particularly suitable for those who use the computer mainly using the keyboard.
- Xfce – is the version of Kali Linux equipped with Xfce, a very light and customizable desktop environment, rather similar to Windows XP.
- Light – this is a variant of the operating system that does not have a desktop environment (which can be added later, after connecting to the Internet). For this reason, the ISO image is smaller than the others. It is recommended for installation on server environments.
- Images for VirtualBox and VMware – these are useful files to virtualize the operating system through the VirtualBox or VMware managers, in a couple of clicks.
Regardless of the type of desktop chosen, to run Kali Linux, it is sufficient that the computer has 1 GB of RAM and, in case of installation on disk, a free partition equal to 20 GB . However, to get a desktop system that is fluid and does not encounter unexpected blocks, I still recommend installing the operating system on a computer equipped with 2 or more GB of RAM .
How to download Kali Linux
Downloading Kali Linux is really very simple. First, connected to the distro website , move the mouse cursor over the Downloads menu (top) and click on the Download Kali Linux item present in the latter.
At this point, find the version of the operating system you are interested in (eg Kali Linux 64-bit ) and click on the HTTP entry in its correspondence, to immediately start downloading the ISO image to be used later.
If you had opted for the use of “pre-packaged” packages for VirtualBox or VMware, you must instead press the link Available on the Offensive Security Download Page and, on the next page, choose the tab relating to the virtualization program you want to use ( VirtualBox or VMware ). To conclude, all you have to do is click on the link relating to the architecture of your interest (32 or 64 bit).
How to install Kali Linux
At the beginning, Kali Linux was conceived as an operating system to be installed and started directly from a USB stick , without leaving traces on the next restart of the PC, nor altering the disk in any way.
This mode, called live , also provides the possibility to save the modified files on the same USB stick, so that they can be used again at the next boot (e.g. personal settings files, dictionaries, packages and so on). However, to date, Kali Linux can be physically installed on the computer’s hard disk (also next to Windows ), through a very simple graphic procedure. Below I will explain everything in detail.
To “install” Kali Linux on a USB stick and start it directly from it, without going to modify the PC hard disk, you must first obtain Unetbootin : a software used to create bootable USB drives, available for free on this website .
To get it, click on the button best suited to the operating system you have (eg Download (Windows) ) and, once you have obtained the program, connect the USB drive on which you intend to install Linux to the PC and start it. If you are using the Mac , remember to copy Unetbootin to your computer’s Applications folder beforehand .
Once the program has started, click on the Yes button , if you are on Windows , or type your administrator password , if you are using macOS , to immediately access the main screen. Then, put the check mark next to the item Disk image located in the new screen that opened, press the button […] to select the previously downloaded Kali Linux ISO, make sure that the item USB drive is selected in the Type drop-down menu and that the drive letter of the stick is specified in the Drive menu .
As I mentioned earlier, Kali Linux also supports persistent boot mode : in this way, it is possible to make the operating system save the files and settings directly to the USB drive when necessary, making them available even on subsequent reboots. To take advantage of this possibility, indicate the amount of space to devote to these files (in MB) in the text field Space reserved for user files that will be protected from various reboots .
Finally, take a last look at the settings defined above and, when you are ready, click on the OK button , to start the creation of the bootable key. The process may take several minutes. If you need additional help on the key creation procedure, I suggest you take a look at my guide on how to create bootable USB stick .
Once the creation of the drive is finished, you just have to boot from it by setting the UEFI or the BIOS of the computer to boot from USB. If you are unable to complete this step yourself, you can rely on the instructions I have provided you with in my guides on how to enter the BIOS and how to install Ubuntu from USB .
If everything went smoothly, at the next boot you should see the Kali Linux choice screen: using the directional arrows, therefore move to the Live item or the Live USB Persistence item (to activate data persistence) and press the Enter key keyboard. After a few seconds, you should see the Kali Linux startup screen: as far as access is concerned, the password of the pre-configured root user is toor .
Disk / Virtual machine
Doesn’t the idea of starting Kali Linux from USB already appeal to you and would you like to do a complete installation on the computer disk? No problem, it’s an absolutely feasible operation. Before explaining how to proceed, however, I would like to make a premise that I consider very important: the installation procedure of Kali Linux, if not performed correctly, could damage or delete the data already present on the disk or, worse still, make the system unusable operating already present.
So, if you have never done such an operation before, I recommend you do some practice using a program like VirtualBox , and then proceed, once you have acquired a sufficient level of experience, to the real installation own on the disc.
If you are not able to create a virtual spot from scratch, you can refer to the same instructions in my tutorial on how to virtualize Ubuntu , with the only trick to replace the ISO image of Ubuntu with that of Kali Linux (which you can download in the same way I explained to you previously).
All clear? OK, let’s go. First, create a bootable USB stick using Unetbootin , as I explained in the immediately previous section . Later, it creates two partitions on the computer’s hard disk, suitable for containing Kali Linux: the first, as already mentioned, must be at least 20 GB and will be used to host the operating system. The second one, that of swap , should be equal to twice the RAM installed on the PC and is used to facilitate communication between the disk and the RAM memory.
How do you say? Have you never created a partition before and just don’t know how to do it? Don’t worry, I have a dedicated partitioning guide ready to guide you step-by-step through this process.
Once the disk partitioning procedure is complete, restart the PC by booting from USB (as I indicated above) and, when you see the Kali Linux choice menu, move to the Graphical Install item and press the Enter key on the keyboard.
Once this is done, you just have to follow the on-screen instructions to carry out the installation of the system: choose the Italian item to set the language, click on the Continue button , select the Italy item and press the Continue button again , choose the Italian keyboard from the list that is proposed to you and, after clicking on Continue again , wait for the system to download the files necessary for installation.
Then type the computer name in the Host Name text field , press the Continue button and do the same for the domain name. If you need to share files over the network with other Windows computers, I recommend using the WORKGROUP domain for compatibility reasons .
At this point, you will be asked to specify a root password , that is the one to be used to access the root account in case of need: enter it in both boxes and click Continue again . Take care to choose a password that you will not easily forget, since it will probably be unrecoverable.
Once this step is also passed, you must specify, in the installation program, the partitions to be used for the installation of Kali Linux: if you want to use an entire disk (keeping in mind that all the data present inside will be deleted ), choose the Guided entry – use the entire disk , click on the Continue button and select the disk in question from the next screen.
If, however, you followed my suggestion and proceeded to manually create the partitions, choose the Manual item , click on the Continue button , choose the partition that must contain the operating system (the one with at least 20 GB), press Continue again and assign it the mount point / following the instructions that are shown to you.
Now, repeat the operation also for the swap partition and, after checking again that the partitions have been correctly selected, choose the item End the partitioning and write the changes on the disk and click on the Continue button . To confirm the changes made, bearing in mind that all data already present on the chosen partitions are irreversibly deleted , set the check mark next to the Yes box and press the Continue button again .
At this point, the system will copy the necessary files to the disk. At the end of this phase, put a check in the Yes box and press twice on the Continue button , so as to configure the Internet sources to be used for future updates.
To conclude, you just have to install the boot loader , the small program that allows you to choose which operating system to start: put the check mark next to Yes again , click on the Continue button , select the main hard drive ( that is, the one that contains the operating system already present on the computer) and click again on the Continue button .
Finally there we are: click again on the Continue button and, to access your brand new operating system, choose Kali Linux from the choice menu that appears on the next boot.
Other methods of installing Kali Linux
In the previous sections, I got to explain you the two main ways to install Kali Linux on your computer. However, they are not the only ones: for example, it is possible to install Kali Linux inside a virtual machine manager ( VirtualBox or VMware ) using the files made available by the development team.
If you have the Windows 10 operating system and you feel quite prepared, you could also “integrate” Kali Linux within Windows, through the WSL (or Windows Subsystem for Linux) functionality available in the latest version of the Microsoft operating system.
For additional information regarding the aforementioned installation methods, I invite you to read carefully my guide on how to install Kali Linux , in which I explained everything in great detail.
How to use Kali Linux
Once the installation of Kali Linux is complete, you can use the operating system exactly as you would any other distribution of this type. As mentioned several times, Kali Linux is full of tools dedicated to penetration testing (i.e. security analysis on networks) and forensic data analysis .
Many of these tools, along with other valuable system utilities, can be called directly from the left sidebar of GNOME 3 (or Dash ). Below I list the software that, by default, can be started directly from the Dash (from the top icon to the bottom one).
- File – is the integrated file manager of GNOME, the one through accessing files, folders and devices connected to the computer.
- Terminal – nothing but the Linux command line, usable for the most disparate operations.
- Leafpad – is the text editor integrated in Kali Linux.
- Firefox ESR – this is a variant of Firefox with extended support, designed for schools and organizations, able to maintain, over time, compatibility with even the most dated operating systems and platforms.
- Burpsuite – is a complete testing suite, oriented towards the discovery and analysis of vulnerabilities characteristic of Web systems.
- Zenmap – this is a utility designed to scan and analyze remote servers and computers (open ports, running services and so on), by IP address.
- Metasploit framework – it is a complete framework for creating testing tools. Metasploit can also be used to design, develop and execute exploits (i.e. programs that exploit vulnerabilities found in programs and operating systems).
- CherryTree – it is a feature-rich clipboard manager.
- Maltego – is a tool dedicated to forensic analysis, capable of comparing, analyzing and superimposing data taken from different sources on the Internet.
- Kismet and fern – these are programs aimed at analyzing security of Wi-Fi networks.
Finally, by pressing the grid- shaped button located at the bottom of the Dash, you can access the complete list of programs installed on the system.
The analysis tools, by default, are organized in many “thematic” folders (depending on the category the software belongs to). In addition, you can access the aforementioned folders by clicking on the Applications item , located in the top bar of GNOME.
Check the security of a Wi-Fi network
How do you say? Have you downloaded Kali Linux to verify that your wireless network is actually secure? I imagined. The undoubtedly most effective method to test the security of a Wi-Fi network is to try to violate it using the tools made available by the operating system. Before delving into this discussion, however, I would like to underline again a very important concept: the information you will find below should be used with conscience , for information purposes only and, above all, without the intention of causing damage to other users. I will not be held responsible for the incorrect use of what you are about to learn.
All clear? OK, then we can start. First, start Kali Linux, then open the Terminal by calling it from the GNOME Dash (or from the desktop application menu) and issuing the following commands, pressing the Enter key on the keyboard each time .
airmon-ng– this command helps you to find the identifier of the network card, specified under the heading Interface .
airmon-ng start wlan0– in this way, go to enable the monitoring function of the network card. Take care to replace wlan0 with the ID found previously.
airodump-ng mon0– this command is used to start monitoring the detectable wireless networks. Remember to replace mon0 with the name of the monitor interface returned by the previous command.
Once you have identified the wireless network to be tested, you can write down its BSSID (you will need it later), its channel , and stop monitoring the networks by pressing the Ctrl + c key combination .
Afterwards, you just have to give the command
airodump-ng -c [canale Wi-Fi] --bssid [BSSID rete] -w /root/Desktop [interfaccia monitor], replacing the values specified in square brackets with the parameters relating to the network (and monitor interface) previously retrieved, and wait for the four-way handshake , i.e. the process through the which the router authorizes a device to access the network. During this process, Kali Linux is able to attack the network and attempt to recover its password.
If, after some time, the operating system does not intercept any handshake, you can provoke one by opening a new Terminal and giving the command
aireplay-ng -0 100 -a [BSSID router] -c [BSSID client] [interfaccia monitor].
If the attack is successful, files will be created , directly on the desktop, which show in clear the password of the wireless network that you have tried to violate. For further information, you can perform a search on Google : on the Net there are numerous guides, in Italian and not, related to the analysis of Wi-Fi networks via Kali Linux.
For the rest, there is not much more to say: you can quickly access specific system folders (the user folder, the desk, the download folder and so on) by clicking on the item Positions , always located at the top. Finally, by moving the mouse to the right of the screen, you have the possibility to see the active desktops and create new ones.
If necessary, you can access the quick system settings (network, audio, battery and more) by clicking on the down arrow located at the top right. To modify them, you must click, instead, on the toolbox button , attached to the menu that appears on the screen.
To quickly create a screencast (i.e. record what is happening on the screen), simply click on the camera- shaped button , located near the system menu.