credit card

Citigroup released new information about the May cyber attack, revealing on June 16 that the hackers accessed the information in over 360,000 North American Citi credit card holders - nearly 1.5 percent of its customers. Previously, Citi had originally announced that approximately 200,000 accounts were affected by the May 24 hack.

Of the 360,083 accounts breached, 217,657 were sent replacement cards and a letter notifying them of the data breach, while the rest were either closed accounts or had already been issued new card information.

Citi says ID theft not an issue

Citigroup says while the names, contact information, and account numbers were stolen, there was no breach of personal information that would allow identity theft or use of credit card data - the hackers did not access birthdates, social security numbers, or credit card PINs.

But despite these reassurances, customers are worried. As reported by The New York Times, Citi is the third largest US bank, yet their response to the breach was slow. The bank only began notifying customers and mailing replacement cards on June 3, a full 10 days after the information was accessed, and the hack wasn't announced officially until June 9, more than two weeks after it occurred.

Citi not the only target of hackers seeking credit card data

Although the size of this breach makes it headline news, the May hack of Citigroup is just the latest in a series of cyber attacks seeking to steal customer credit card information from major companies. Google, Sony and Lockheed Martin have all been the target of hackers, forcing data security experts and regulators to step up their game in order to protect consumers from risk. Their rate of success will determine whether the next major hack is prevented - or goes unthwarted as hackers attempt to steal personal and business credit card information.