Shares of United Natural Foods (UNFI) sank Monday after the company said that its business operations were disrupted by "unauthorized activity" on its IT systems.

UNFI, which has a distribution agreement in place with Amazon's (AMZN) Whole Foods Market through 2032, wrote in a regulatory filing that it "became aware" of the activity last Thursday.

The company said it "promptly activated its incident response plan and implemented containment measures, including proactively taking certain systems offline, which has temporarily impacted the Company’s ability to fulfill and distribute customer orders."

Shares of UNFI were recently down more than 8%.

UNFI said it "is working actively to assess, mitigate, and remediate the incident with the assistance of third-party 澳洲幸运5官方开奖结果体彩网:cybersecurity professiꦡonals and has notified law enforcement."

Shares of UNFI, which is slated to report 澳洲幸运5官方开奖结果体彩网:fiscal third-quarter results before the opening bell Tuesday, fell into negative territory for the year following the disclosure.