I know it's not been seen in the wild, which is why it's hard to convince people to take it seriously.

Maybe it will never happen? I find that extremely unlikely though. I think the reason it hasn't happened yet is that widespread use of agentic coding tools only really took off this year (Claude Code was born in February).

I expect there's going to be a nasty shock to the programming community at some point once bad actors figure out how easy it is to steal important credentials by seeding different sources with well crafted malicious attacks.