Of course she's behind it. Hannity has been saying for weeks now that the whisper campaign / rumor is directed straight at him as being the one who has a damaging tape about Michelle. He's the natural target for Hillary to pin it on, since he was the first to interview Jeremiah Wright way over a year ago on his show.
Unfortunately for Hillary, people are wise to her tactics and that includes the 'RATS who are supporting Obama. They will blame her (not Republicans) for "dirty tricks" against Obama because they know that she will stop at nothing in order to "steal the nomination" from him. Obama's supporters will never vote for her in the general if she gets the nomination. Likewise, very few of Hillary's supporters will vote for Obama.
Thanks to Operation Chaos, the 'RAT party is now divided and will be conquered regardless of which one gets the nomination.