U.S. Energy Department says cyber hack limited to business networks only

The U.S. Energy Department said on Thursday that it was responding to a cyber breach related to the Solar Winds hack that was isolated to business networks.

"At this point, the investigation has found that the malware has been isolated to business networks only, and has not impacted the mission essential national security functions of the Department, including the National Nuclear Security Administration," said spokeswoman Shaylyn Hynes in a release.