> What can I do to prevent it?

My two most precious digital possessions - my email and my Bitwarden account - are protected by a Yubikey that's always on my person (and another in another geographical location). I highly recommend such a setup, and it's not that much effort (I just keep my Yubikey with my house keys)

I got a bit scared reading the title, but I'm doing all I can to be reasonably secure without devolving into paranoia.

If the software gets poisoned then your YubiKey will not save you.