(NEW YORK) -- Target confirmed a major data breach at stores nationwide involving millions of credit and debit card numbers.
Approximately 40 million accounts may have been affected between Nov. 27 and Dec. 15. In a statement Thursday, the retailer said it has identified and resolved the issue, and is working closely with law enforcement and financial institutions to investigate the problem.
Target alerted authorities and financial institutions after it was made aware of the unauthorized access.
"Target's first priority is preserving the trust of our guests and we have moved swiftly to address this issue, so guests can shop with confidence," said Gregg Steinhafel, Target's chairman, president and chief executive officer. "We take this matter very seriously and are working with law enforcement to bring those responsible to justice."
Identity theft expert Adam Levin, who is the former director of Consumer Affairs for New Jersey, said this isn't the first time a major retailer has been targeted.
"TJ Maxx suffered a massive breach several years [ago]. Heartland Payment Systems, which isn't a retailer, but it's a payment process [that] experienced a massive breach as well," he said.
Robert Siciliano, a security analyst, says data breaches are rising. He has been working with large companies like McAfee to stop these types of unauthorized access.
"Often it's due to insiders, those who are inside the organization, either because of malicious activity or simply because of mistakes they're making," Siciliano said.
Many people use their cards without care or concern, but Siciliano warns that people should still pay attention to their statements and refute unauthorized charges. As long as you're paying attention to your account, Siciliano adds, "[merchants] will reset the clock and you'll get all the money back in your account," under the zero liability policies at most stores.
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