(ABC NEWS) -- Federal authorities were investigating a breach into computer systems of at least one U.S. nuclear power plant, sources familiar with the matter told ABC News.
There was no evidence that any particularly sensitive or operational systems were breached. Instead, authorities believe only a less sensitive, business-associated side of systems was compromised in at least one breach detected over recent months.
The breach was first reported by E&E News, which covers the energy and environment sectors.
E&E noted the hack did not garner the attention of the public safety alert systems at the Nuclear Regulatory Commission or the International Atomic Energy Agency, which could be further evidence of a low-risk level associated with the breach.
One U.S. official called this an "ongoing matter" that was still being investigated. No public word has been given on who may be responsible, but authorities were looking at the possibility that a nation-state may be behind the hack.
It was unclear if the case is related in any way to other known cyberattacks.
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