Instructions on signing VirtualBox and VMware modules for Secure Boot · GitHub

How to launch/repair your #Vagrant box with #Virtualbox on an #Ubuntu Box with #SecureBoot with Linux Kernel 4.4+

Here is the tip to fix it once
▻http://askubuntu.com/questions/760671/could-not-load-vboxdrv-after-upgrade-to-ubuntu-16-04-and-i-want-to-keep-secur/768310#768310

Here is tip to fix it for good (on each kernel upgrade)
▻https://gist.github.com/gabrieljcs/68939c7eeadfabfdbc6b40100130270d

$ openssl req -new -x509 -newkey rsa:2048 -keyout MOK.priv -outform DER -out MOK.der -nodes -days 36500 -subj "/CN=John Doe/"

BTW, you might require this to allow #vagrant to run your VirtualBox 5.1
▻https://github.com/mitchellh/vagrant/issues/7588#issuecomment-233035591