Install VirtualBox

<?php
$URL="https://raw.githubusercontent.com/panticz/installit/master/install.virtualbox.sh";
echo "wget $URL -O - | bash -";
echo "

";
$c = curl_init();
curl_setopt($c, CURLOPT_URL, $URL);
curl_setopt($c, CURLOPT_RETURNTRANSFER, 1);
echo htmlspecialchars(curl_exec($c));
curl_close($c);
echo "

";
?>
--allow-unauthenticated

Fix kernel module
sudo /etc/init.d/vboxdrv setup

Links
http://wiki.ubuntuusers.de/VirtualBox/Installation
http://www.virtualbox.org/wiki/Linux_Downloads
http://www.panticz.de/node/143