Target says investigators have found that hackers stole credentials from a vendor to access the retailer's systems and pilfer about 40 million debit and credit card numbers as well as personal information for another 70 million people.
Spokeswoman Molly Snyder declined to comment Wednesday on further details, such as the vendor's identity or how the hackers stole the credentials, citing the ongoing the investigation.
Snyder did say that since Minneapolis-based Target Corp. confirmed the breach on Dec. 15, it has taken extra precautions such as limiting or updating access to some platforms.
Last week, some card numbers of Target customers from South Texas turned up in the arrest of a pair of Mexican citizens at the U.S.-Mexico border. But experts believe the attack's original perpetrators will be difficult to locate.