WASHINGTON - Hackers suspected of working for the Russian government have allegedly cracked into the unclassified White House computer networks causing temporary disruptions.
White House officials, who spoke on condition of anonymity, said that cyber teams were partly successful in containing the intrusion as they know who hacked into the network and also the extent of data that may have been compromised.
They said that the intruders apparently did not cause damage to any of the systems, and to date, there is no evidence that the classified network was hacked.
"In the course of assessing recent threats, we identified activity of concern on the unclassified Executive Office of the President network," Associated Press quoted one White House official as saying.
"We took immediate measures to evaluate and mitigate the activity....Unfortunately, some of that resulted in the disruption of regular services to users. But people were on it and are dealing with it."
However, the White House officials didn't say who was behind the attack.
"Certainly a variety of actors find our networks to be attractive targets and seek access to sensitive information," the White House official said. "We are still assessing the activity of concern."
However, some cyber security firms have tipped the officials that they have identified cyber espionage campaigns by Russian hackers thought to be working for the government in Moscow.
Sources said the security firms have also identified targets, including NATO, the Ukrainian government and US defense contractors.
Russia is said to be in the top tier of states listed by the US with cyber capabilities.
Another White House official told Politico that the suspicious activity on unclassified networks was discovered by security personnel.
"In the course of assessing recent threats, we identified activity of concern on the unclassified [Executive Office of the President] network," the official told the American political journalism organization based in Arlington County, Virginia.
The official, without divulging details, expressed confidence that the systems at the White House have not been damaged.
"In this case, we took immediate measures to evaluate and mitigate the activity. Our actions are ongoing, and some have resulted in some temporary outages and loss of connectivity for our users.
"Our computers and systems have not been damaged, though some elements of the unclassified network have been affected. The temporary outages and loss of connectivity for our users is solely the result of measures we have taken to defend our networks."
The FBI, Secret Service and National Security Agency were all involved in the investigation.