Sam’s Club, an American warehouse supermarket chain owned by U.S. retail giant Walmart, is investigating claims of a Clop ransomware breach.

The Walmart division operates over 600 warehouse clubs with millions of members across the United States and Puerto Rico and almost 200 additional locations in Mexico and China.

Sam’s Club has over 2.3 million employees and reported a total revenue of $84.3 billion for the fiscal year ending January 31, 2023.