One chestnut from my history in lottery game development:
While our security staff was incredibly tight and did a generally good job, oftentimes levels of paranoia were off the charts.
Once they went around hot gluing shut all of the “unnecessary” USB ports in our PCs under the premise of mitigating data theft via thumb drive, while ignoring that we were all Internet-connected and VPNs are a thing, also that every machine had a RW optical drive.
Yeah, it’s surprisingly simple to get these microcontrollers to become essentially programmable keyboard/mouse emulators, by which point if you’re familiar with the stuff to program them (Arduino being the simplest and most widespread framework) it really just becomes a coding task and you can get it to do crazy stuff.
I suggested an Arduino Micro board because it bypasses the whole hardware side of the problem, but something like what you mention is even simpler.