Reuters reported that payment card data was stolen from an unknown number of Target Corp customers starting on the busy Black Friday weekend in a major breach at the U.S. retailer.

The attack was so severe The Secret Service is investigating. Investigators believe the data was obtained via software installed on machines that customers use to swipe magnetic strips on their cards when paying for merchandise at Target stores.

Krebs on Security, a closely watched security industry blog that broke the news, said the breach involved nearly all of Target’s 1,797 stores in the United States, citing sources at two credit card issuers. The report said that “track data” from at least 1 million payment cards was thought to have been stolen before Target uncovered the operation, but that the number could be significantly higher.

These attacks seems to become more common and maybe one day the cheque book might return.