A spokeswoman for Heritage Valley Health System says the attack Tuesday is affecting the entire health system and they are working to ensure safe patient care continues.
Heritage Valley is a $480 million network that provides care for residents of Allegheny, Beaver, Butler and Lawrence counties, in Pennsylvania; parts of eastern Ohio; and the panhandle of West Virginia.
It wasn't immediately clear if it was related to the outbreak of malicious data-scrambling software that appears to be causing mass disruption across Europe Tuesday.
RELATED: New cyberattack causes mass disruption globally
Spokeswoman Suzanne Sakson says the health system is using the same emergency procedures it employs during any disaster.
Also affected is New Jersey-based Merck, the second-largest drugmaker in the United States with extensive operations in the Philadelphia area.
Merck confirmed its computer network was "compromised" as part of the global attack.
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