BLOOMINGTON, Minn. - Last week, Aimee Gunderson got 21 text messages in a row from her bank stating her credit card was denied; however, she wasn't out shopping -- she was at work.

"There were some charges out in Sweden, some from Germany and in France," she said.

Gunderson believes the cyber attacks on Target are to blame. Hackers were able to get credit and debit card information from 40 million shoppers.

The security breach could not have come at a worse time for Target as consumers finish up their holiday shopping.

Carlson School of Management professor Akshay Rao said Target's biggest problem right now is consumer trust.

"Now, suddenly this concern might have an impact on their willingness to shop at Target and they might choose to, for big ticket items, go to one of their competitors or shop online," Rao said.

This weekend, Target is offering a one-time 10 percent discount and free fraud monitoring, but Rao doesn't believe that's enough to get some shoppers back.

"Giving a 10 percent discount is, I think, addressing the wrong problem. People are not concerned that Target was priced too high. People are concerned, those of them sitting on the fence, are concerned that their financial security is at risk, and so that's the problem that needs to be addressed" he said.

Gunderson isn't one of those customers waiting on the sideline. She's been back to Target three times since the breach. She said her credit card company reversed all the unauthorized charges and she feels safe with a new card.