To be able to enjoy seamless integration between the host operating system and the VirtualBox guest you have to install VirtualBox Additional Tools on the guest operating system.

To do so, follow the steps:

Ensure you have a working Internet connection.

Step 1:

Install requirements for the Additional Tools:

sudo apt-get install gcc linux-source-virtual linux-headers-virtual dkms

Reboot after installation.

Step 2:

After logging in again find the Install Additional Tools option on the Devices menu.

Then on your guest mount the cdrom:

sudo mount /media/cdrom

Step 3:

Now install the tools:

cd /media/cdrom

./VBoxLinuxAdditions-x86.run

This will install the additional tools for virtual box.

Reboot your system and you’re all set.