I have the same problems with: Kernel 4.4.0-143-generic Virtualbox 5.2.26 r128414 Ubuntu 16.04.6 LTS
My workaround: Select previous Kernel 4.4.0-142-generic through "GRUB Customizer". Reboot.
No rebuild/reinstall of VBox components neccessary.
I have the same problems with:
Kernel 4.4.0-143-generic
Virtualbox 5.2.26 r128414
Ubuntu 16.04.6 LTS
My workaround:
Select previous Kernel 4.4.0-142-generic through "GRUB Customizer".
Reboot.
No rebuild/reinstall of VBox components neccessary.