Back in the 90s mIRC would download files to the root directory of mIRC itself -- long before the concept of separating user data and code became the norm on Windows -- and if people had "auto accept file transfers" enabled people could send you a viral "script.ini" (as I recall it was called) to you and immediately overwrite your customisations. The end result would spread rapidly as the infected users would share it with others who join and left the channels they were in.
Ah, yes, I remember that. I think it was because the modems didn't differentiate between the various layers in the transport stream and took anything resembling low-level modem commands to be gospel.
