As you can see from the screenshot above (large version here) the real launcher apparently is replaced with a fake launcher that sends the user to a web site that pretends to be official, asking for subscription information (including answers to secret questions and the original CD-Key) in what is meant to appear as the means to restore a supposedly suspended account. One of the telltale signs that this isn't legit, besides the very invasive information requested, is the version number in the upper left corner of the screen. We're way past patch 3.1.1 -- however not everyone might know this.
Ancilorn posts confirming that this is not genuine (reiterating that they will never ask for your password in such a manner, and also requesting that such things be sent directly to Blizzard if they happen to you). Goes to show that as security is increased, those looking to breach it become more desperate.