Data from 40 million credit and debit cards used at Target may be compromised

Shoppers wait in line at Target on the Thanksgiving Day holiday in Burbank, California, November 22, 2012.
Photo by Photo by Jonathan Alcorn/Reuters

Between Nov. 27 and Dec. 15 data from 40 million credit and debit cards might have been stolen from 1,797 Target retail stores, according to security blogger Brian Krebs who broke the story Wednesday. Target announced on Thursday that the corporation resolved the issue on December 15.
The theft is the second largest card-security breach on a U.S. retailer.

The U.S. Secret Service is investigating the security breach. The security blog Krebs on Security said that investigators believe that the data was obtained via software installed on card readers at checkout lines.

No one knows how the checkout machines were compromised, said Molly Snyder, spokeswoman for Target.

“It is very clear it is a sophisticated crime,” she said.