Sandwich chain 'wichcraft recently began notifying an undisclosed number of customers that their credit or debit card information, including names, payment card numbers, security codes and expiration dates, may have been exposed when the company's servers were accessed by an unauthorized party.

Customers who made purchases at 'wichcraft locations in New York or San Francisco using a credit or debit card between August 11, 2013 and October 2, 2013 may have been affected.

"After learning of this incident, we quickly took steps to secure the system to help prevent this type of issue from reoccurring," 'wichcraft president Jeffrey Zurofsky wrote in the notification letter [PDF]. "We are working with law enforcement authorities in their investigation of the incident and also working closely with the relevant payment card brands to share information about the incident."

The company isn't offering any credit protection services to those affected, but all recipients of the notification letter are being advised to review their account statements and credit reports for fraudulent activity.

Customers with questions are advised to contact (866) 942-4272, ext. 6.

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