Costly cyber attacks are having a bigger impact on corporate earnings and are becoming a fact of life for companies as Oreo cookie maker Mondelez, drug maker Merck and others said that a destructive “worm” attack in the last week of the second quarter disrupted operations.

Mondelez International Inc., the world’s second-largest confectionary company, reported a 5 percent drop in quarterly sales on Wednesday, blaming shipping and invoicing delays caused by the June 27 attack of the worm, known as NotPetya.

Other NotPetya victims include Merck & Co. Inc., which last week warned that NotPetya had halted production of some drugs, saying it has yet to understand the full costs associated with the attack.

The attack also slowed deliveries at FedEx Corp., disrupted port operations of shipping company A.P. Moller-Maersk A/S and halted production lines at British consumer goods maker Reckitt Benckiser PLC, according to accounts by those companies.

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