Supermarket breach exposes 4.2M accounts

PORTLAND, Maine -- A security breach at an East Coast supermarket chain exposed more than 4 million card numbers and led to 1,800 cases of fraud, the Hannaford Bros. grocery chain announced Monday.

Hannaford said credit and debit card numbers were stolen during the card authorization process and about 4.2 million unique card numbers were exposed, placing the case among the largest data breaches ever.

The breach affected all of its 165 stores in the Northeast, 106 Sweetbay stores in Florida and a smaller number of independent groceries that sell Hannaford products.

The company is aware of about 1,800 cases of fraud reported so far relating to the breach. No personal data such as names, addresses or telephone numbers were divulged — just account numbers.

Hannaford became aware of the breach Feb. 27. Investigators later discovered that the data breach began on Dec. 7; it wasn't contained until March 10, said Carol Eleazer, Hannaford's vice president of marketing in Scarborough.

"We have taken aggressive steps to augment our network security capabilities," Hannaford president and CEO Ronald C. Hodge said in a statement released Monday. "Hannaford doesn't collect, know or keep any personally identifiable customer information from transactions."

The company urged its customers to monitor their credit and debit cards for unusual transactions and report any problems to authorities. It also told customers to beware of e-mails and calls from people claiming to represent Hannaford and seeking any personal information.

The U.S. Secret Service, whose duties include investigating electronic crimes such as data breaches, confirmed it's investigating but declined to comment on the scope of the crime.

"The company did contact us, and we are investigating," said agency spokesman Malcolm Wiley.

MasterCard, the second-biggest U.S. credit card association after Visa, issued a statement before Hannaford's disclosure: "Because this incident is the subject of an ongoing law enforcement investigation, we cannot disclose additional details regarding the incident or otherwise comment at this time."