Citigroup says 360,000 affected by hackers

Jun 16, 2011

Hackers stole account information of more than 360,000 of Citigroup Inc.'s U.S. credit card customers in a recent data breach, the bank said Wednesday, almost double the number initially thought.

Citi said last week that about 1 percent of its credit card customers had information hacked online but did not say exactly how many. The actual number of customers affected was thought to be about 200,000, based on Citi's 2010 annual report, which said the company had roughly 21 million North American customers.

But the true number was actually 360,083, the bank said in a statement posted on its website late Wednesday.

The bank said it discovered on May 10 that hackers used its Account Online system to access the data for North America Citi-branded credit cards issued in the U.S.

The bank said last week that hackers accessed customer names, account numbers and contact information, including e-mail addresses.

But they weren't able to get their hands on , dates of birth, card expiration dates or card security codes, information that can be useful in identity theft.

Internal fraud alerts and enhanced monitoring were placed on all accounts deemed at risk as soon as the breach was discovered, Citi said.

Letters were sent starting June 3 to people affected, and 217,657 customers have also been sent new cards, Citi said. Replacement cards were not sent to the others because the accounts were closed or they had already been sent new cards for other reasons.

Citi said it has notified police and .

"For the security of our customers, and because of the ongoing law enforcement investigation, we cannot disclose further details regarding how the data breach occurred," it said.

Citi reassured customers that they weren't liable for any unauthorized use of their cards and urged them to review account statements to report any suspicious transactions.

It's the latest in a series of high-profile data attacks against big companies and institutions. The International Monetary Fund said Sunday that it was investigating an attack on its computer system.

Google Inc. said earlier this month that Gmail accounts of several hundred people had been breached. In April, Sony Corp.'s Playstation Network was the victim of a massive security breach that affected more than 100 million online accounts.

Explore further: Research shows impact of Facebook unfriending

not rated yet
add to favorites email to friend print save as pdf

Related Stories

Latest data breach strikes at financial security

Jun 11, 2011

(AP) -- Citigroup's disclosure that the names, account numbers and email addresses of 200,000 of its credit card customers were stolen strikes at the core of modern-day financial life - the ways people buy ...

Sony says 25 million more accounts hacked

May 03, 2011

Sony Corp. said Monday that hackers may have taken personal information from an additional 24.6 million user accounts after a review of the recent PlayStation Network breach found an intrusion at a division that makes multiplayer ...

US banks, companies issue warning after email hack

Apr 04, 2011

Computer hackers gained access to the email addresses of customers of several large US banks and other companies in a potentially huge data breach at US online marketing firm Epsilon. ...

More Sony websites hacked, 8,500 Greek accounts hit

May 24, 2011

Sony on Tuesday said its websites in three countries had been hacked with 8,500 Greek user accounts compromised, in a blow to efforts to restore confidence after a huge data breach affecting millions.

Recommended for you

Research shows impact of Facebook unfriending

14 hours ago

Two studies from the University of Colorado Denver are shedding new light on the most common type of `friend' to be unfriended on Facebook and their emotional responses to it.

LinkedIn membership hits 300 million

Apr 18, 2014

The career-focused social network LinkedIn announced Friday it has 300 million members, with more than half the total outside the United States.

Researchers uncover likely creator of Bitcoin

Apr 18, 2014

The primary author of the celebrated Bitcoin paper, and therefore probable creator of Bitcoin, is most likely Nick Szabo, a blogger and former George Washington University law professor, according to students ...

User comments : 0

More news stories

Old tires become material for new and improved roads

(Phys.org) —Americans generate nearly 300 million scrap tires every year, according to the Environmental Protection Agency (EPA). Historically, these worn tires often end up in landfills or, when illegally ...

Mantis shrimp stronger than airplanes

(Phys.org) —Inspired by the fist-like club of a mantis shrimp, a team of researchers led by University of California, Riverside, in collaboration with University of Southern California and Purdue University, ...

Volitional control from optical signals

(Medical Xpress)—In their quest to build better BMIs, or brain-machine-interfaces, researchers have recently begun to look closer at the sub-threshold activity of neurons. The reason for this trend is that ...