Problem : "How I can install Vbox addons in my Debian Jessie VM ?"

Solve :
- Insert addons disk
- Update your distribution (update / upgrade)
- Mount the disk with "mount media/cdrom"
- Install (if you don't have) build-essential dkms gcc
- Make temp folder with "mkdir /tmp/vboxaddons"
- Copy the disk "cp -r /media/cdrom0/* /tmp/vboxaddons/"
- Go in vboxaddons folder ("cd /tmp/vboxaddons/")
- Run "./VBoxLinuxAdditions.run"
- Restart your VM