How awful! I'm not much of a tech expert either, but if the Zoom meeting was open rather than requiring a password, it's very likely that whoever did this will never be caught. I mean unless they're really stupid, which is always a possibility. If they aren't candidates for the Darwin awards, then they probably used proven methods to encrypt their identity.
How awful everyone had to experience that, though. And what an awful commentary on human nature that somebody apparently thought it was funny to do this.