First you should install „virtualbox vm extension pack” on site https://www.virtualbox.org/wiki/Downloads
after that add right to user:
to check your user is in group execute command:
szymon : szymon adm cdrom sudo dip plugdev lpadmin sambashare libvirtd libvirtd vboxusers
If you have problem of showing usb list
ls -lR /dev/vboxusb
shows
razem 0
drwxr-x--- 2 root vboxusers 120 lis 28 19:37 002
drwxr-x--- 2 root vboxusers 60 lis 28 19:37 003
/dev/vboxusb/002:
razem 0
crw-rw---- 1 root vboxusers 189, 131 lis 28 19:37 004
crw-rw---- 1 root vboxusers 189, 132 lis 28 19:37 005
crw-rw---- 1 root vboxusers 189, 133 lis 28 19:37 006
crw-rw---- 1 root vboxusers 189, 134 lis 28 19:37 007
/dev/vboxusb/003:
razem 0
crw-rw---- 1 root vboxusers 189, 257 lis 28 19:37 002
execute command:
chmod 777 -R /dev/vbox*
then normal user szymon will display