BILOXI -- A breach discovered in December by Landry's Inc. and Golden Nugget Hotels and Casinos affected some customers who used their credit cards at Golden Nugget Biloxi, the company said in a press release.
According to the press release, findings from an investigation "show that criminal attackers were able to install a program on payment card processing devices at certain restaurants, food and beverage outlets, spas, entertainment destinations and managed properties."
Landry's hired a cyber-security firm to investigate in early December after the company received a report of "suspicious activity regarding cards that had been legitimately used in some of our locations."
The investigation showed the program was designed to search for data -- cardholder name, card number, expiration date and internal verification code -- after a card was swiped on a breached system.
In Biloxi, different areas in the Golden Nugget were affected at different times:
-- H20 Pool Bar, from May 5 to Dec. 3
-- Starbucks, from May 10, 2014, to March 14 and from May 8 to Dec. 3
-- Golden Nugget Banquets/Buffet, from May 8, 2014, to March 14 and from May 7 to Dec. 3
"Enhanced security measures, including end-to-end encryption, have been implemented to prevent a similar issue from occurring in the future, and we continue to support law enforcement's investigation," the press release said. "We are also working closely with the payment card networks to identify potentially affected cards so that the card issuers can be made aware and initiate heightened monitoring of those accounts."
Landry's said it would send a letter or email to customers who used their cards at affected locations during the data breach. Customers are asked to report unauthorized activity to the card issuer.
The company released a full list of affected locations online.
Golden Nugget General Manager Chett Harrison declined to comment.