Target data breach affects at least 70 million customers

The data breach at Target Corp over the holiday shopping season was far bigger than initially thought, the company said today, as state prosecutors announced a nationwide probe into the second-biggest retail cyber attack on record.

Target said an investigation has found that the hackers stole the personal information of at least 70 million customers, including names, mailing addresses, telephone numbers and email addresses. Previously, the No.3 U.S. retailer said the hackers stole data from 40 million credit and debit cards.

The two sets of numbers likely contained some overlap, but the extent was not clear, according to Target spokeswoman Molly Snyder. She also noted that some of the victims did not shop at Target stores during the period of the breach between November 27 and December 15, and their personal information was stolen from a database.