Information of 21 million bank card holders in North America stolen
Citigroup has confirmed that hackers have breached the bank’s network and stolen information of around 21 million bank card holders in North America.
Names of customers, account numbers and contact information are believed to be compromised in the attack. However, the bank said that date of birth and card security codes were safe.
The Financial Times had earlier reported that the bank had discovered the breach in early May. It has been criticised for delay in informing its customers about the data theft.
"We are contacting customers whose information was impacted. Citi has implemented enhanced procedures to prevent a recurrence of this type of event," a Citi spokesman Sean Kevelighan said in a statement to Reuters.
"For the security of these customers, we are not disclosing further details."
Another Citi spokesman James Griffiths in Hong Kong told Reuters that the breach had affected about 21 million or 1% of North American card customers.
Security experts have warned that hackers may use the stolen data to dupe users.
The bank has not said how the breach took place.
Citigroup joins a growing list of companies, including EMC, Lockheed martin and Sony, to face cyber attacks.
Last month, Sony was heavily criticised and also sued in US courts for delay in informing customers about the PSN data breach it suffered in April. Sony had taken nearly a week to confirm the breach.