Officials at Wolf Creek have said no "operations systems" have been affected. The hacking doesn't appear to have breached any "operations systems" to control the facilities themselves but did breach administrative networks. A 2015 study by the British think-tank Chatham House found nuclear control systems to be "insecure by design" and vulnerable to attack.
Meanwhile, in this particular case, the identity and motive of the hackers is yet to be revealed.
Industry experts and USA officials say the attack is being taken seriously, in part because of recent events in Ukraine.
Ukraine is now host to what may turn into a full-blown cyberwar, Greenberg reported.
Fraser Kyne, EMEA CTO at Bromium said: "Whether this creates a disaster such as a hazardous spillage or power outages for millions, or something less dramatic like a heap of business disruption for the plants that have been attacked, its clear security has to change".
Hageman says Wolf Creek has been operating safely and continues to.style="text-align: center;"
Russia is suspected to be behind recent cyber-intrusions at power plants. Oliver Nicolaas Ponder Eye Em Via Getty Images
A separate Homeland Security technical bulletin issued on June 28 included details of code used in a hacking tool that suggest the hackers sought to use the password of a Wolf Creek employee to access the network.
Security specialists often use such language to describe hackers backed by governments, according to the Times.
However, a May 23 news release issued by Maria Korsnick, president and CEO of the Nuclear Energy Institute, said Trump's proposed budget doesn't sufficiently support the nation's existing reactors.
The Department of Homeland Security has called cyber attacks on critical infrastructure "one of the most serious national security challenges we must confront".
The FBI warning came in the form of a security document that was leaked. Authorities say they are unsure.
These latest suspicions towards Russian Federation come on the heels of a colossal cyberattack that crippled countries and corporations across the globe, which cybersecurity experts said Russian Federation may have perpetrated.
The hacks come against the backdrop of increasing global tensions over United States intelligence agencies' conclusion that Russian Federation tried to influence the 2016 presidential election.style="text-align: center;"