Email virus
I am still fairly proud that I discovered a previously unknown virus at a customer site, mid 90s. It snuck in via outlook express, and distributed itself by setting a signature block. Their antivirus (symantic I think) didn't spot it, even when scanning an isolated example and I couldn't find a reference on the various av vendor sites. Submitted it to them, and it was duly added a day or two later. Thankfully it wasn't anything destructive..
I did only find it because one of the users spotted that their usual signature had vanished... They dealt a lot with manufacturers in China so I suspect it came in that route, but never did trace the source properly.
Biting the hand that feeds IT
