I wonder if I would have been saved by my absolute disdain for installing anything Microsoft Teams-related on my computer. The web version works fine, thanks.
"the meeting said something on my system was out of date. i installed the missing item as i presumed it was something to do with teams, and this was the RAT."
That's the bit that scares me. I've often found myself installing software in a hurry to join a meeting on some platform that I've not previously used via my current machine.
The time pressure means I'm less likely to pay attention to what I'm installing.