The White House has acknowledged an attempt to infiltrate its computer system, but says it thwarted the effort and no classified networks were threatened.
White House spokesman Jay Carney told reporters the White House was equipped with mitigation measures that identified the attack, isolated it and prevented its spread.
He said there was no indication that any data were removed.
“There are distinctions between those networks that contain classified information and those that don’t, and the attack was against an unclassified network,” Carney said.
Carney described the attack as “spear-phishing” and said such efforts against government computer systems were “not infrequent.” Carney spoke in Henderson, Nev., where President Obama is preparing for his first debate against rival Mitt Romney on Wednesday.
“Phishing” is a tactic that involves sending an email that falsely claims to be from a legitimate enterprise in an attempt to trick the user into turning over information.
Last year, Google Inc. blamed computer hackers in China for a phishing effort against Gmail accounts of several hundred people, including senior U.S. government officials and military personnel. In November, senior U.S. intelligence officials for the first time publicly accused China of systematically stealing American high-tech data for its own national economic gain.
The White House would not say whether the recent attack was linked to China.