Officials say suspicious activity has been detected on White House computer systems, while they refuse to comment on reports pointing to Russia as a prime suspect.
A White House spokesman said immediate action was taken to address the suspicious activity detected on their network.
So far there is no information available about who may be behind the attack or when exactly it occurred.
The attack targeted the unclassified network of Barack Obama. Security measures taken led to temporary network outages and loss of connectivity for some White House employees. The Washington Post reports that intranets and VPNs were down, while email remained unaffected, apart from "minor delays."
A White House official said: “Undoubtedly, there are several actors who see our networks as an attractive target and seek access to sensitive government information.”.
"We are still in the process of assessing the attack, and we are not able to provide additional details at this time," he added.
The White House declined to comment on the Washington Post report, which said Russia was behind the attack. Russian intelligence agencies have previously been accused of hacking US military computer systems.
