Last month, Target announced that millions of shoppers' data was accessed by hackers.
The company said today that sales have been hurt by the breach, which is one of the biggest in history. As many as 70 million people are affected.
And it could take Target a long time to recover.
YouGov BrandIndex measured consumer perception of Target by asking adult customers "if you've heard anything about the brand in the last two weeks, through advertising, news, or word of mouth, was it positive or negative?"
Since the breach, consumer perception has plunged. This could make shoppers choose a competitor like Wal-Mart instead.
Here's a chart showing the plunge:
