CHARLESTON, South Carolina -- Former Secretary of State Hillary Clinton laughed off a new attack ad from a Republican super PAC run by Karl Rove during an interview Sunday on “This Week” with George Stephanopoulos.

The web spot, titled “Hillary’s Bull Market,” was launched by American Crossroads, which is run by the Republican strategist and former President George W. Bush adviser. After watching the ad for the first time during her interview on “This Week,” Clinton just smiled.

“I think it shows how desperate the Republicans are to prevent me from becoming the nominee,” Clinton said about the ad, which goes after her ties to Wall Street. “I find that, in a perverse way, an incredibly flattering comment on their anxiety, because they know that not only will I stand up for what the country needs, I will take it to the Republicans.”

“Wall Street made her a multimillionaire,” the ad says about Clinton, “Does Iowa really want Wall Street in the White House?”

“It kind of boosts me up,” Clinton explained, "I assume he thinks that I am going to get the nomination and he’s trying to interfere with the Iowa caucus to maybe confuse people on the way to caucus for me.”