US Nuclear Regulatory Commission hacked 3 times in 3 years

According to documents obtained under an open-records request, two of the hacks, perpetrated via phishing emails, are believed to have originated in foreign countries, while the source of the third remains unknown because incident logs have been destroyed. The report does not say when the attacks occurred, nor does it divulge what, if any, data was compromised.
Naked Security – Sophos