(Newsroom America) -- U.S. law enforcement and national security officials are investigating a China-based hacker attack on a sensitive computer system utilized by the White House Military Office that handles top-secret data, a report said Wednesday.
The Washington Free Beacon, which initially reported the attack, also said that congressional Republicans have asked the White House to "provide details of the attack on the White House Communications Agency, which runs the Situation Room and classified communications and teleconferences."
Meanwhile, the website, quoting unnamed U.S. officials, said President Obama was not immediately informed of the attack, which was traced to servers in China, but instead was informed later.
The Beacon said the FBI, along with the U.S. Secret Service, is conducting an investigation into the attack. National Security Agency officials are also involved.
On Monday, White House spokesman Jay Carney acknowledged that attack, which he characterized as "spear phishing," which is a form of cyber attack utilizing emails that attempt to convince recipients to provide confidential information.
"The attack … was what’s known as a spear-phishing attack against an unclassified network," he told reporters during a presidential campaign swing through Las Vegas.
Carney played down the incident and did not provide many details, reports said.
"Let’s be clear: this is an unclassified network,” Carney said. “These types of attacks are not infrequent, and we have mitigation measures in place."
"In this instance, the attack was identified, the system was isolated, and there is no indication whatsoever that any exfiltration of data took place,” he said, adding that the attack “never [had] any impact or attempted breach of any classified system."
The Beacon said U.S. intelligence estimates China has about 2,000 hackers who engage in cyber warfare efforts on behalf of the government in Beijing.
© 2012 Newsroom America.