This encompasses the various things I do whenever I'm setting up a new Kali VM in Virtualbox.

Proxy Configuration

Configure proxy (if applicable) by inputting the required values into /etc/environment. It will probably look something like this:

http_proxy=www.proxy.com:80
https_proxy=www.proxy.com:80
no_proxy=.proxy.com,localhost,127.0.0.1

Resource: https://askubuntu.com/questions/175172/how-do-i-configure-proxies-without-gui

Config apt with proxy (if applicable):
touch /etc/apt/apt.conf.d/95proxies

Input the required values into this file. It will probably look something like this:

Acquire::http::proxy "http://www.proxy.com:80";
Acquire::https::proxy "http://www.proxy.com:80";
Acquire::ftp::proxy "http://www.proxy.com:80";

Restart the server :
reboot

Welcome back, your proxy should be working now. Celebrate by taking a snapshot.

Install all of the updates

This will get you the latest and greatest:

apt update
apt upgrade -y
apt dist-upgrade -y

Install the VirtualBox Guest Additions:

apt update
apt install -y virtualbox-guest-x11

Install the linux headers:

uname -r
apt install -y linux-headers-*
reboot

Take a snapshot.

Resources:
https://www.ceos3c.com/hacking/install-kali-linux-virtualbox-guest-additions-june-2017-edition/
https://docs.kali.org/general-use/kali-linux-virtual-box-guest
https://www.youtube.com/watch?v=lvY-Qn54W98

Install docker

curl -fsSL https://download.docker.com/linux/debian/gpg | sudo apt-key add -
echo 'deb https://download.docker.com/linux/debian stretch stable' > /etc/apt/sources.list.d/docker.list
apt update
apt install -y docker-ce

Start docker automatically upon reboot:

systemctl enable docker

Resource: https://medium.com/@airman604/installing-docker-in-kali-linux-2017-1-fbaa4d1447fe

Configure docker with proxy

mkdir /etc/systemd/system/docker.service.d
touch /etc/systemd/system/docker.service.d/http-proxy.conf

Setup docker with the proxy by inputting the required values into /etc/systemd/system/docker.service.d/http-proxy.conf. It will probably look something like this:

[Service]
Environment="HTTP_PROXY=http://www.proxy.com:80/"

Restart the server :
reboot

Take a snapshot.

At this point, if you need to install any certs in your browser or configure your browser to work with your proxy, follow the instructions provided by your corporate IT provider.

Install firefox addons that you need like foxyproxy.

Configure foxyproxy with Burp

Download and install foxyproxy
Click on the foxyproxy icon, click Options
Click Add
Specify Burp Suite for the Title
Specify localhost for the DNS name
Specify 8080 for the port
Click Save

Install Burp cert

Run burpsuite
Select the Burp Suite profile we created in FoxyProxy previously
Navigate to localhost:8080
Click CA Certificate
Click Save File
Click the icon with the three lines in firefox (found the the upper right-hand side of the window)
Click Preferences
Search for certificate
Click View Certificates
Click Import
Select cacert.der in the Downloads folder, click OK
Check the box next to Trust this CA to identify websites, click OK

Navigate to https://www.google.com/ to verify that everything is working.

At this point, you should be good to go.

Fix for invalid signature on update

This means you haven't updated for a while, and that's very bad. Don't do that. However, if you run apt update and get an invalid signature error, run this command: wget -q -O - https://archive.kali.org/archive-key.asc | apt-key add

Kali Config