NEW YORK JPMorgan Chase & Co mailed incorrect replacements for payment cards to about 4,000 people for the state of Connecticut after personal data stored at the bank was accessed in a cyber attack this summer.
The bank made the mistake as it tried to reissue Connecticut-branded cards to pay unemployment compensation and tax refunds for the state, according to an announcement from Connecticut Treasurer Denise Nappier.
JPMorgan notified the state of the error on Thursday, the statement said.
Nappier said: "This latest error heightens my concern about the company. I continue to be greatly disappointed with its performance and its obvious lack of attention to detail."
A bank spokesman said the company caught the error part way through the mailing. The security breach had affected 14,335 accounts in Connecticut and some 465,000 across the country.
JPMorgan disclosed two weeks ago that it discovered in September that web servers used by its site www.ucard.chase.com for prepaid cards had been breached.
The bank has not seen any improper use of the exposed information, the spokesman said on Friday.
In a separate cyber attack, retailer Target Corp said on Thursday that hackers had stolen data from up to 40 million credit and debit cards of shoppers who visited its stores during the first three weeks of the holiday season.
(Reporting by David Henry in New York; Editing by Ken Wills)