Chinese hackers attack computer systems of White House, US presidential candidates

This is not the first time, China has been blamed for hacking into the servers of the US government.

The US government officials strongly believe that Chinese hackers had successfully penetrated Pentagon networks in 2007 and more recently, they had snooped into Barrack Obama's and John McCain's presidential election campaign networks to steal their policy data - information that might be useful in negotiations with a future administration.

Officials at the FBI, which is investigating the incident, have confirmed that the campaign systems of the presidential candidates were hacked into by a "foreign entity or organization" and not by their political opponents.

"You have a problem way bigger than what you understand," a Federal agent had told Obama's team, which thought that their computer systems had been invaded by a phishing virus - malware designed to steal credit-card numbers.

"You have been compromised, and a serious amount of files have been loaded off your system," the agent said.

According to a Newsweek report, after FBI warned of the security breaches, Obama's camp had hired a private cyber security firm to plug the network leaks.