Follow the below steps to install virtualbox on Arch Linux based Systems.
[Install VirtualBox and VirtualBox Host Module on Arch Linux] $ sudo pacman -S virtualbox virtualbox-host-modules-arch
[Load VirtualBox module to the kernel] $ sudo modprobe vboxdrv
[Install Virtualbox Extension Pack] $ yaourt virtualbox-ext-oracle
[Adding Your Account to the vbox User Group] $ sudo gpasswd -a $USER vboxusers