My personal view is that the operating systems we trust to be the foundation of our modern devices simply shouldn't allow that kind of access to most applications. Installing software that genuinely does need some level of privileged access to do its job -- perhaps device drivers, or diagnostic tools for people who work in hardware development and really do need to test low level I/O -- should require a different process from the user's perspective.
That process for privileged installation should come with prominent warnings telling the user not to do it unless they're sure you know who's asked them to and why, and perhaps require the user to enter some sort of text confirmation in response to avoid accidental/auto-pilot click-throughs. The need for this kind of installation should be rare enough for normal users, particularly if the OS is designed to run most third party drivers in user space anyway, that this wouldn't be a big deal for usability.
Maybe then even banks might think twice about trying to pull that kind of stunt, if they would have to field many calls from concerned customers over the next 48 hours asking whether someone was trying to hack their bank account. Perhaps they'd even make it into the news as a result, and have to explain why their software was triggering security warnings, which could be nicely embarrassing PR too.