The base package should be downloaded only from a trusted source, for instance the official website http://www.virtualbox.org. The integrity of the package should be verified with the provided SHA256 checksum which can be found on the official website.

General installation instructions for the supported hosts can be found in Installation Details.

On Windows hosts, the installer can be used to disable USB support, support for bridged networking, support for host-only networking and the Python language binding. See Installing on Windows Hosts. All these features are enabled by default but disabling some of them could be appropriate if the corresponding functionality is not required by any virtual machine. The Python language bindings are only required if the API is to be used by external Python applications. In particular USB support and support for the two networking modes require the installation of Windows kernel drivers on the host. Therefore disabling those selected features can not only be used to restrict the user to certain functionality but also to minimize the surface provided to a potential attacker.

The general case is to install the complete package. The installation must be done with system privileges. All binaries should be executed as a regular user and never as a privileged user.

The provides additional features and must be downloaded and installed separately, see Installing and Extension Packs. As for the base package, the SHA256 checksum of the extension pack should be verified. As the installation requires system privileges, will ask for the system password during the installation of the extension pack.