U.S. officials say Russian government hackers have penetrated energy and nuclear company business networks

Russian government hackers were behind recent cyber-intrusions into the business systems of U.S. nuclear power and other energy companies in what appears to be an effort to assess their networks, according to U.S. government officials.  The U.S. officials said there is no evidence the hackers breached or disrupted the core systems controlling operations at the plants, so the public was not at risk. Rather, they said, the hackers broke into systems dealing with business and administrative tasks, such as personnel.At the end of June, the FBI and the Department of Homeland Security sent a joint alert to the energy sector stating that “advanced, persistent threat actors” — a euphemism for sophisticated foreign hackers — were stealing network log-in and password information to gain a foothold in company networks. The agencies did not name Russia.The campaign marks the first time Russian government hackers are known to have wormed their way into the networks of American nuclear power companies, several U.S. and industry officials said. And the penetration could be a sign that Russia is seeking to lay the groundwork for more damaging hacks.