Some guy has paid for a high occurrence advertising spot on adf.ly meaning at least 80% of the time you go on adf.ly or an adf.ly link you will be vulnerable to this guy's exploit pack.
I don't know how long it will last or anything, but I suggest you stay away from adf.ly links for now. I was almost nearly the slave of one of these links. You are probably already infected if you aren't using a good antivirus and have UAC enabled.
So don't take the risk! Don't get infected.
Thanks.