Office supply giant Staples said on Friday that point-of-sale (PoS) systems at 115 of its more than 1,400 U.S. retail stores were infected by malware as a result of a recently discovered data breach.
Overall, Staples believes that roughly 1.16 million payment cards may have been affected as a result of the compromise.
“Staples believes that malware may have allowed access to some transaction data at affected stores, including cardholder names, payment card numbers, expiration dates, and card verification codes,” the company said in an incident update notice. “At 113 stores, the malware may have allowed access to this data for purchases made from August 10, 2014 throughSeptember 16, 2014. At two stores, the malware may have allowed access to data from purchases made from July 20, 2014 through September 16, 2014.”
The company said that during the investigation it received reports of fraudulent payment card use related to four stores in Manhattan, New York at various times from April through September 2014. However, the investigation found no malware or suspicious activity related to the payment systems at those stores.
A list of stores affected by the PoS malware and dates can be found here.
Staples first said that it was investigating the possible theft of customer credit card files in late October.