The restaurant chain Zaxby's said that a data breach may have compromised its patrons' card information.

The company announced on Jan. 11 that it found suspicious files, including malware, on computer systems at some of its locations. It found the files after being informed by credit card processors that some of its restaurants had been identified as the sites of possibly fraudulent charges.

The malware, Zaxby's says, may have been used to steal diners' names and credit and debit card information. The company said it is working with the authorities on an investigation and is trying to establish additional security at all its locations.

Zaxby's said it believes the breach came from an external source.

The chain has so far identified 108 restaurants whose computer systems have been affected, or nearly one-fifth of its 560 locations. The affected stores are located in Alabama, Florida, Georgia, Kentucky,  Mississippi, North Carolina, South Carolina, Tennessee and Virginia.

Known for its chicken fingers and dipping sauces, Zaxby's operates throughout the South and Texas.