Democratic presidential candidate Hillary Clinton is surprised that Sen. Bernie Sanders attacked her in his latest TV ad.

And although Sanders did not specifically mention Hillary by name, what he said was rather an obvious shot at her and her alleged Wall Street support.

Sanders personally narrated the ad and said, "There are two Democratic visions for regulating Wall Street. One says it's OK to take millions from big banks, and then tell them what to do." As noted, Hillary is known for her long time association with the so-called "big banks" of Wall Street, and is reportedly one of her major backers.

Sanders continued, "My plan: Break up the big banks, close the tax loopholes and make them pay their fair share."

But Business Insider noted that despite the seemingly direct attack to Hillary, Sander's ad may be considered relatively tame compared to the usual fun fare that U.S. politics has witnessed.

Still, Clinton's campaign manager Robby Mook is not too pleased, and said that their whole campaign team was surprised with the attack. He clarified that the reason they were surprised is because Sanders himself, personally guaranteed that he will never run a negative advertisement.

Mook also made a subtle jab of their own and said that, with this latest ad, Sanders is not really that different from other politicians his campaign had portrayed to be. In addition, Clinton's camp also reiterated that the ad was a clear attack on the former U.S. Secretary.

When asked if their camp will respond with a similar move, the Clinton camp just said that they would wait on what the senator will do, The Guardian reported.

Over the campaign period, Hillary's camp has allegedly made repeated subtle jabs to Sanders over his record of gun control and even released a TV ad to highlight the issue.

But the Sanders camp countered and said that the Vermont senator's latest commercial is not directed at Hillary, but rather the whole Democratic Party that thinks it's okay to take Wall Street funding and then expect to control these big corporations.

The Sanders camp also noted that Hillary Clinton is obviously part of the establishment, which Wall Street showered with financial support -- a stark contrast with Bernie, who does not have a favorable relationship with these institutions.

But according to The Observer, the Sanders camp remains firm and said, "The day he would have to get into a negative exchange with Hillary Clinton is the day the campaign is over."