Landry's Inc., the dining and hospitality chain operator that discovered a long-running data breach in December 2015, announced it has completed its internal investigation into the incident, and has fortified its point-of-sale operations with encryption technology to prevent future cyberattacks.

According to a company statement, an investigation spearheaded by a contracted cybersecurity firm determined that bad actors installed malware on payment card processing devices used at various Landry's properties, including Landry's Seafood, Rainforest Cafe, McCormick & Schmick's and its affiliated Golden Nugget hotel and casino operations.

A sequence of three attacks—each one affecting different locations—took place between May 4, 2014 and Dec. 3, 2015, during which the malware stole data from the magnetic stripe of customers' payment cards. The Houston-based company owns more than 500 establishments, nationwide.