UNFI supplies over 30,000 grocery stores and signed a deal last year to supply Whole Foods through 2032

United Natural Foods Inc. (UNFI), the main distributor for Whole Foods and other grocery stores, suffered a major cyberattack, forcing it to take some systems offline.

The company detected unauthorized activity on June 5 and is now investigating with help from law enforcement. UNFI warned of temporary disruptions to its operations and is working to restore affected systems.

Customers have already reported empty shelves and smaller deliveries at Whole Foods stores. A Reddit post showed a sign saying products were “temporarily out of stock.”

UNFI supplies groceries to over 30,000 retailers and signed a deal last year to supply Whole Foods through 2032.

Shares of UNFI dropped over 9% in early trading.