Ответ: http://download.virtualbox.org/virtualbox/5.0.2/Oracle_VM_VirtualBox_Extension_Pack-5.0.2-102096.vbox-extpack
VirtualBox Extension Pack.
Support for USB 2.0 devices, VirtualBox RDP and PXE boot for Intel cards. See this chapter from the User Manual for an introduction to this Extension Pack. The Extension Pack binaries are released under the VirtualBox Personal Use and Evaluation License (PUEL).
По ссылке - для последней версии.