Introduction
Katoolin is a collection of scripts for automating the installation of Kali linux tools in different platforms other than Kali linux, and installing Kali linux tools with Katoolin in other OSs or Windows Subsystem for Linux is always less secure than installing the same tools in Kali Linux. Kali Linux is named after the Hindu goddess of destruction which should give the user some indication that even Kali Linux itself is risky and difficult to manage, especially for new users.
Katoolin draws its tools from a variety of sources including apt and GitHub. Katoolin doesn't know anything about the platform that it is running on, so the safest way to use Katoolin is to install each tool the hard way one tool at a time, checking each time to see if that tool is included in the default Ubuntu repositories and if so installing it that way instead. When the installation is finished, the software sources that were added by Katoolin should be immediately disabled in order to prevent Katoolin from replacing packages that were installed from the default Ubuntu repositories with its own updated packages whenever Ubuntu software is updated.
Installation of Kali linux tools
(Re)install Katoolin as follows:
Open the terminal and type:
sudo apt install git
git clone https://github.com/LionSec/katoolin.git && sudo cp katoolin/katoolin.py /usr/bin/katoolin
Make /usr/bin/katoolin executable.
sudo chmod +x /usr/bin/katoolin
Run Katoolin as follows and you will see the Katoolin interface:
cd /usr/bin/
sudo ./katoolin
View the categories of available software in katoolin interface
Press 0 to install all Kali linux tools.
When you go to View Categories and then enter 0 for all, the installer will immediately return to where you were. Scroll up, and you'll see that a number of the packages can't be found. Those packages are no longer maintained or have been removed from the Kali repositories. Even with this issue, you'll still find a lot of the Kali software available for installation.
So the best option is to install Kali linux tools in a series of distinct steps. Just like if you want to install Forensic tools on your system, then choose its option from the category and then type 0 to install all forensics tools. If this still doesn't work, then you have to install whatever forensic tools that can be installed one package at a time.
This is why the Katoolin interface sometimes hangs when you try to install all of the Kali linux tools at once. Take the time of waiting for the server to respond to a request for a package that is not available and multiply it by how many unavailable Kali linux tools there are in the Katoolin repositories.
If you wish to go back to the main menu, type gohome in your katoolin interface. Now select the option 3 or 4 to install either the classicmenu indicator or the Kali menu. Press the y key to continue and then press Enter to start its setup.
Once you are done with installation of Kali tools using katoolin, you can quit by pressing the keyboard combination Ctrl+C and you will see the goodbye message.
shutdown requested....Goodbye...
Credit for the above text block goes to Kashif at How To Install Kali Linux Tools On Ubuntu 16 And CentOS 7 with my additions italicized.
Warning about updates after installing Kali linux tools
The LionSec Katoolin GitHub webpage clearly warns Katoolin users to be careful when updating software.
Before updating your system, please remove all Kali-linux repositories to avoid any kind of problem.
In case of problems with logging in: it could be that purging deleted a needed file in /home/$USER/ or it changed permissions on a needed file. If the problems occur before login it is more than likely related to the video card driver.
1st thing to do is to go to a TTY (control alt f1). You can use apt-get to re-install ubuntu with:
sudo apt-get install ubuntu-desktop
(or any other desktop) or re-install your video card driver or re-configure your video card.
If that is not possible you can also do this from the grub prompt or from a live session.
As a future method of doing this: do not mess with your OS. Install virtual box or vm ware and install Ubuntu in that. Make a copy of the container and you can mess with desktops all day long. Restore the container and all is back to normal.
Best Answer
Warning about updates after installing Kali linux tools
The LionSec Katoolin GitHub webpage clearly warns Katoolin users to be careful when updating software.
All kinds of problems can occur if you don't do this.
Additional reference: How to install Kali linux tools in Ubuntu 15.10
Katoolin is a script that makes it quick and easy to install may Kali linux tools at the same time, however adding Kali repositories is not always necessary. For example read this answer to a question about how to install only two Kali linux tools, which can also be easily installed without adding Kali repositories.
Adding only the Kali linux tools that you need manually is good training that teaches you how to use the other package management tools that are provided by the default Ubuntu repositories and which are safer than Katoolin because they don't add a long list of additional repositories to your software sources.
If you need to install a lot of Kali linux tools you should also consider installing Kali Linux itself, either as a dual boot or in a virtual machine. If you have done what looks like irreparable damage to your system with Katoolin, I recommend that you remove all the Kali linux repositories that you added from your software sources and with the help of the terminal
historycommand remove all the packages that you installed with Katoolin, and start over again with vanilla Ubuntu.