Heartland data breach could be the largest in US history

Details are emerging on what could well become that largest data breach in US History.

Heartland, a company that processes payments for more than 250,000 businesses, is saying today that up to one million customers may have had their credit information stolen, a number easily eclipsing the 47 million customers potentially at risk of credit fraud from the TJX data breach a few years ago. Heartland has since called U.S. Secret Service and hired two breach forensics teams to investigate.

The breach was discovered late last year as fraud activity from Visa and MasterCard cards began to spike; the affected cards at all been used at establishments serviced by Heartland's credit card processing centers.

Robert Baldwin, Heartland's president and chief financial officer, told the Washington Post that 40 percent of transactions the company processes come from small to mid-sized restaurants across the country. He declined to name a specific restaurant.

Brian Krebs at Washingtonpost.com has the details, as does ComputerWorld.