"the meeting said something on my system was out of date.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." Oh dear.
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.
Getting rushed by a 3rd party into doing sth one would do more carefully normally is probably a good tell that it's a social engineering attempt.