Massive data breach occurred at TARGET, the third-largest U.S. Retailer during last Christmas Holidays. Breach was caused by a malware attack, that allowed the criminals to manipulate Point of Sale (PoS) systems without raising red flags and the card numbers compromised in the breach are now flooding underground forums for sale. The hackers have all 40 Million payment card details, but the PINs are encrypted with Triple-DES (Data Encryption Standard), which is a highly secure encryption standard.
Source: https://thehackernews.com/2014/01/hackers-behind-target-data-breach-are_10.html