Citigroup said that a hacker attack in May was nearly double the number of accounts by the bank initially estimated . A total of 360,073 accounts from U.S. credit cards were affected by the invasion Citigroup, the bank said in a statement on Wednesday (15).
Of those affected, 217,657 new cards and customers received a letter of notification, while other accounts were inactive or had previously received new cards, the bank added.
Citigroup had earlier reported that about 1% of their accounts in North America were hit. The institution’s annual estimates their number at 21 million account holders.
“The discrepancy is due, in general, the fact that our number of accounts is higher than reported by the annual balance of 2010, and factors such as the fact that some of the accounts were closed,” said Sean Kevelighan, spokesman Citigroup in the United States.
Hackers gained access to names, account numbers and contact information of customers.However, Citi said it “critical information to commit fraud have not been compromised,” and that other online systems for its retail banking division had not been affected.
Citigroup also said it had identified “most” of compromised accounts in seven days and added that the data on the accounts were obtained by the invaders on May 24. Nevertheless, customers only began to be reported on June 3.