By AJ Vicens

(Reuters) -United Natural Foods Inc ( UNFI ) one of the largest U.S. grocery distributors whose clients include Whole Foods, took certain systems offline in recent days after the discovery of unauthorized activity on internal networks, the company said on Monday. 

A Whole Foods spokesperson told Reuters in an email on Monday that the company was "working to restock our shelves as quickly as possible" and referred additional questions back to United Natural.

Shares of United Natural fell more than 8% during Monday's session and closed down by almost 7% at $25.94.

United Natural, based in Rhode Island, said in a June 9 filing with the Securities and Exchange Commission that it "proactively" took some systems offline after becoming aware June 5 of unauthorized activity on certain networks.

The company said the incident temporarily hurt its "ability to fulfill and distribute customer orders." It added that the incident "is expected to continue to cause temporary disruptions" to its operations. 

There have been a spate of cyber incidents affecting major retailers in the UK and the U.S. recently, including Marks & Spencer ( MAKSF ), Co-op, Harrods and Victoria's Secret.

United Natural did not specify the "unauthorized activity." In the past, disruptions that caused companies to take actions similar to those it described have often been linked to ransomware incidents, where extortion-minded cybercriminals disable a firm's computers by encrypting them, promising to release the decryption key only in exchange for massive cryptocurrency payments.

United Natural Foods ( UNFI ) is the largest publicly traded wholesale distributor of "healthier food options" in the U.S. and Canada, according to its website. In May 2024 the company announced an eight-year extension to serve as primary distributor for Amazon ( AMZN )-owned Whole Foods.

The FBI did not immediately respond to a request for comment.

United Natural Foods ( UNFI ) reported $8.2 billion in net sales in the 13-week period ending February 1, 2025.