http://www.w5j6stm77zs6652pgsij4awcjeel3eco7kvipheu6mtr623eyyehj4yd.onion/wiki/VirtualBox/Guest_Additions
The Guest Additions package includes drivers and utilities that enhance the performance and usability of the VMs. Guest Additions provides features such as seamless mouse integration, shared folders between the host and guest operating systems, improved graphics performance, and the ability to resize the guest display dynamically.