I got a similar virus on my computer and it ruined it.. Took it to my ex who fixes these things. They were finally able to get my files, but could not even reload the operating system. This is a very bad bug.
But,,You can pick this up from anywhere on the net and it is not always the last thing you looked at that infected it.. It could lay dormant until you reboot.. then when it starts to be active.. it starts in one place, spreads inside your computer and everything you do after it starts just makes it worse.
I do know that some of the smileys carry virus ...
No way that I know of to know exactly where it came from.
I am in agreement that it most likely wasnt the board itself, but perhaps a link. I have found bugs in some of the links posted