US banking giant Citigroup had told its clients that about 360,000 credit cards were affected by an online hacking attack in May.
Citigroup reported that the security breach had compromised a total of 360,083 Citi-branded credit cards, but it declined to provide further details, citing the ongoing investigation and its customers’ security.
The company has come under scrutiny from US legislators for its handling of the attack. Citi did not inform its clients of an early May attack until nearly a month later.
Citi is one of the world’s largest providers of credit cards, with more than 21 million accounts and is owed more than $77 billion only in North America, according to its 2010 annual report.
