Banking giant says 3,400 customers were affected by a breach of the company's online account system in May, The Wall Street Journal reports.
About 3,400 Citigroup credit card customers suffered a loss of $2.7 million during a security breach earlier this year, according to a Wall Street Journal report.
Citi acknowledged earlier this month that a May 10 breach compromised the company's online account system, allowing the attackers to access names, account numbers, and contact information for the affected customers. However, Citi said that Social Security numbers, birth dates, card expiration dates, and card security codes were not compromised.
The banking giant said its customers will not be liable for the losses.
Citi originally said the breach affected about 1 percent of its 21 million customers, or about 210,000 customers. Citi later raised the number of compromised accounts to 360,083.
Citi began notifying its affected customers and replacing the compromised credit cards when it announced the intrusion. So far, Citi has issued more than 217,000 new credit cards along with a notification letter.
A state-by-state breakdown published by Citi showed how many customers in each state were affected by the beach, with California, Texas, Illinois, New York, and Florida logging the most incidents.