The company had previously said 40 million shoppers had their credit and debit card information stolen in the weeks following Thanksgiving.
Target said the hacking is not a new breach, but that it was discovered as part of the investigation into the theft of card information.
Target also said Friday that sales had been stronger than expected before its original announcement on Dec. 19 but fell sharply after the news. Target (TGT, Fortune 500) warned that sales and profits for the current quarter would be lower than expected because of that loss of consumer confidence.
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