Over the past three years, the US Nuclear Regulator Commission (NRC) has been hacked three times. In one incident, unnamed foreign hackers sent hundreds of phishing emails targeting 215 staff.

Phishing was used in all three attacks. dozens of staff were conned into entering their login details into fake web forums, as well as by tricking employees into downloading and executing malware hosted on a Microsoft SkyDrive account and contained within an attached PDF file.

The report did not mention if any data was or could have been compromised.

The NRC systems were not connected to nuclear facilities. NRC communications chap Scott Burnell wrote on their website: "The NRC's computers cannot affect US nuclear power plant operations – the plants' safety and control systems are physically isolated and have no Internet connectivity."