Yeah, thats it. It has been around in several different variations, saying different things, but its the same thing.
http://www.imchaos.com/alert.asp
I have a bunch more links at school about it I can post when I get back. Its not hard to remove, there is a program (av.exe, IIRC) that is running in the background that is doing it. After killing and deleting it, things go back to normal.