When news of Target's data breach hit last week, there was no doubt that consumers would be up in arms, caught up in a mixture of anger and panic.
YouGov's Brand Index, which measures daily brand perception among consumers, has quantified that reaction.
In the week leading up to the breach—which resulted in the theft of account information from about 40 million credit and debit cards used at the retailer's stores—Target logged a consumer perception of 26, more than twice the average for all big holiday chain stores. But as of Monday, the company's rating had plummeted to -29.2, according to YouGov.
Scores range from 100 to -100 and are determined by subtracting negative feedback from positive. A score of zero means that a company has received equal positive and negative feedback from respondents.
(Read more: Banks could sue over Target breach)
The days following the breach mark the first time since June 2007 that the retailer has rated below 10. The deep descent indicates that the consumer pullback analysts predicted has become a reality.
"I think it is going to make a material difference on [Target's] earnings probably through 2014," Michael Farr, president of Farr, Miller & Washington, told CNBC.
(Read more: Weak U.S. card security made Target a juicy target)
YouGov compiles its data by interviewing 4,300 people on each weekday. It asks respondents, "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?"
—By CNBC's Krystina Gustafson. Follow her on Twitter @KrystinaGustafs.