Avoid nonfree software
|For system security it is strongly advised to not install proprietary, non-free software. Instead, use of free software is recommended. As free software pioneer Richard Stallman puts it:
Open Source software like Qubes, Linux and Whonix is more secure than closed source software. The public scrutiny of security by design has proven to be superior to security through obscurity. This aligns the software development process with Kerckhoffs' principle - the basis of modern cipher-systems design. This principle asserts that systems must be secure, even if the adversary knows everything about how they work. Generally speaking, Libre Software projects are much more open and respectful of the privacy rights of users. Libre Software projects also encourage security bug reports, open discussion, public fixes and review.
Possible risks associated with using Non-free software: