WASHINGTON -- Russian hackers were behind a cyber intrusion into a non-classified White Housecomputer network, CNN said on Tuesday.
During an interview of CNN's "The Situation Room", Deputy White House National Security Adviser Ben Rhodes said that no classified information had been compromised, but he declined to link any attacks to Russia.
"We do not believe our classified systems were compromised," Rhodes said, adding that the White House is constantly updating its unclassified system and that personnel are told to act as if information on that network could be compromised by hackers.
According to the report, the FBI, Secret Service and U.S. intelligence agencies are all involved in investigating the breach, which they consider among the most sophisticated attacks ever launched against U.S. government systems.
The intrusion was routed through computers around the world, as hackers often do to hide their tracks, but investigators found tell-tale codes and other markers that they believe point to hackers working for the Russian government, the report said.
U.S. intelligence officials say that the pace and sophistication of Russian-sponsored attacks have increased as tension over Ukraine has grown and the U.S. has imposed economic sanctions on Russia, it said.
On CNN's report, FBI spokesman Paul Bresson declined to comment while White House National Security Council spokesman Mark Stroh said that CNN's report didn't refer to any new incident.
Last year, some U.S. media also reported that U.S. security officials have suspected the Russian criminal hackers of being behind the October attack on a White House computer system.
