KYRA PHILLIPS, CNN ANCHOR: Now, you might want to check your credit card accounts. A hacker's handiwork has compromised millions more credit numbers -- or more card numbers rather, than first thought. Now banks are scrambling to protect those accounts. CNN's Fred Katayama is joining us live from New York with the latest. Not a real good story, Fred. FRED KATAYAMA, CNNfn</s>CORRESPONDENT: No, Kyra, a scary one. We've got the latest numbers; a hacker has gained access to more than five and a half million VISA and MasterCard accounts. MasterCard and VISA said the hacker breached the security of a company that processes credit card transactions on behalf of merchants. A spokesman for the two associations said they promptly notified the affected banks that issued the cards; 5.6 million cards were accessed, that's nearly 1 percent of the 574 million VISA and MasterCard's in the United States. A bank serving the Northeast, Citizens Bank, said it shut down the accounts of 8800 customers whose card numbers had been accessed. A bank spokeswoman said all those accounts were safe. A VISA official added that none of the compromised cards have been used fraudulently. A MasterCard spokeswoman couldn't say whether any of its cards had been improperly used. MasterCard and VISA wouldn't disclose how many banks they've notified nor would they say whether this was a regional or a national problem. We tried to reach the largest card issuers, but only one, First USA Bank, returned our calls. It said it was not affected and was not aware of security problems affecting its customers. Security experts I spoke to say credit card breaches involving merchants are rather common. But breaking through the security of a merchant processor is rare. MasterCard says it is working with authorities, including the FBI, to help identify the culprit -- Kyra.</s>PHILLIPS: All right, our Fred Katayama. Thank you so much. TO ORDER A VIDEO OF THIS TRANSCRIPT, PLEASE CALL 800-CNN-NEWS OR USE OUR SECURE ONLINE ORDER FORM LOCATED AT www.fdch.com Hacking>
More than 5 Million Credit Accounts Compromised in Hacking