This is very strange indeed. Especially the death part seems rather peculiar and almost directly out of a creepy Pasta.
That being said, I'm not certain where you are trying to install VBox on? Inside a Whonix Workstation or on a specific host?
If you are using Ubuntu, I'd rather use
sudo apt-get install virtualbox virtualbox-qt virtualbox-dkms
and not some deb package.
Have a nice day,