On Friday, Krebs posted another story detailing how he had tracked down phony cards made using information that was stolen as part of the Target data breach:
"Credit and debit card accounts stolen in a recent data breach at retail giant Target have been flooding underground black markets in recent weeks, selling in batches of one million cards and going for anywhere from $20 to more than $100 per card, KrebsOnSecurity has learned."
On Thursday, Target confirmed that someone had hacked into its systems and had stolen 40 million debit and credit cards from stores across the country. The breach apparently lasted from Black Friday to Dec. 15.
As expected, the thieves are using that information obtained from those credit cards to make phony copies that are being sold on black market stores around the world, Krebs found.
At just one site that sells such counterfeit cards, Krebs said, he helped one bank find 100 cards for sale that were made using information obtained from customers who were affected by the Target breach.