A senior U.S. official said the direct connection of the industrial control systems (ICS) handling the country's critical infrastructure networks to the internet has led to an uptick in penetrations during the past year.

Marty Edwards, director of the Department of Homeland Security's Industrial Control Systems Cyber Emergency Response Team (ICS-CERT), told security pros, speaking before security pros at the S4 ICS Security Conference in Miami said the industrial control systems “are just hanging right off the tubes,” according to Reuters.

Edwards did not disclose whether or not the successful attacks that took place in the U.S. resulted in any damage or outages.

Edward's concern is highlighted by Ukrainian power grid attack last month when Russian actors allegedly knocked out electricity to tens of thousands of people.