Since my original post on running Kali Linux in Docker on Windows 10 I have been able to robustly test and refine this set up. I have used this setup to undertake challenges on Hack the Box and Vulnhub, but perhaps what gave these setup a real test was using it on real penetration testing engagements. This post is designed to complement the original to demonstrate the improvements I have made.

Improvement 1: I Was Stupid

In my orignal post, I talked about using Cmder to allow me to use multiple windows. What I originally was doing was creating up to four containers at a time to run applications or access files. There may be some benefits to this such as seperation and allocation of resources, however it was a pain to share files etc.. So I began running a single container and using tmux. I ended up moving away from user Cmder as it could not handle enabling the mouse in tmux. I moved to powershell.exe and had similar issues, not to mention clashes with the colours of my bash shell and the colours of powershell. In the end I have ended up using trusty old cmd.exe which has been great!

Improve 2: GUI Applications

I was typically getting by not needing too many of Kali’s GUI applications. The ones I did need, were typically .jar files and I was able to run these on Windows. The Applications I was using heavily were - Burp Suite, Dirbuster and OWASP ZAP. However, I still wanted to get GUI applications working and I tried a wide number of guides I found on the internet. In the end, what ending up working was the following:

  1. Install MobaXTerm
  2. Start MobaXTerm
  3. Click the Settings button (not the drop down menu)
  4. On the X11 tab change ‘X11 remote access’ to Full

Then start your container with the -e parameter to give the BASH variable the value of your IP Address. (This should be the IP address of your host machine on the Hyper V NAT network). To do this add the following

 docker run --it -rm -e DISPLAY=172.20.128.1:0 kali tmux

Now, you will be able to run GUI applications by calling them from the terminal.

Improvement 3: Shared Folders

Whilst doing penetration testing engagements I found I often needed to get my files from the container onto the host machine so I can store or submit them. I started doing this with the Python SimpleHTTPServer and navigating with my Host’s browser to download, but if I forgot to open the ports to do this, I would need to spin up another container and start sharing across multiple containers. It was a pain. The easiest way I have found was to simply create a folder titled ‘DockerFiles’ and then everytime I spin up a container I map this folder on the host to a folder in my containers home directory and I have instaneous access to files from the container. To run this, I simply enter the following:

 docker run --it -rm -e DISPLAY=172.20.128.1:0 -v C:\DockerFiles:/root/DockerFiles kali tmux

Improvement 4: .bat files

So, as you can see from above, typing all that in can become a bit of a pain. So I found that writing a simple .bat file to execute the docker commands was the way to go. Since, docker needs to be run as an administrator I found after I created the .bat file, I made a shortcut of it and set it to run as Administrator. This way I was prompted for my Administrator password everytime I ran the file to create a container. My .bat file looks like this:

 start cmd.exe /K docker run -it --rm -v C:\DockerFiles:/root/DockerFiles -e DISPLAY=172.20.128.1:0 kali tmux

Conclusion

I really enjoy running my Kali instance like this. The biggest reason for me is that since I am on a Surface Pro 4, I always have issues with scaling of some applications. So running Kali in VMWare was always tiny and a strain on the eyes. This way my command prompt is native and I can run all my command line applications as I want and when I run GUI applications they are scalled perfectly for my display. tmux has been amazing and has boosted my productivity immensely, shared folders are fantastic so I can simply open up files as they pop into the folder. If you are going to run Kali in docker, the improvements I have detailed here are must haves for your set up.