The White House is confirming an attempted cyberattack on its computer system, but said it thwarted the effort.
The Obama administration is not identifying the source of the attack, while a published report accuses China.
Citing an unnamed source, the Associated Press reports that "a White House official said the attack targeted an unclassified network. He said the attack was identified and that the system was isolated to prevent spread. He said there was no indication that any data was removed."
The AP added: "The official, who was not authorized to speak on the record about the attack, said there was no attempted breach of classified systems. The official described such 'spear phishing' attacks as 'not infrequent.'"
The Washington Free Beacon reported over the weekend that "hackers linked to China's government broke into one of the U.S. government's most sensitive computer networks, breaching a system used by the White House Military Office for nuclear commands, according to defense and intelligence officials familiar with the incident."
The report added: "One official said the cyber breach was one of Beijing's most brazen cyberattacks against the United States and highlights a failure of the Obama administration to press China on its persistent cyberattacks.