Hackers working for the Russian government were able to access President Obama's email system inside the White House, CNN reported Tuesday, indicating that an earlier breach may have been more serious than previously thought.
The State Department and the White House said late last year they had seen suspicious activity in their networks, though the White House said at the time only unclassified systems were affected. That may have been true, but it understated the sensitivity of the information accessed, CNN reported Tuesday, citing unnamed U.S. officials briefed on the investigation.
While the White House designates its email system as "unclassified," it still contains sensitive information that could be valuable to foreign spies. The information accessed included real-time, non-public details about Obama's schedule, CNN reported.
The Russian hackers used their earlier breach of the State Department's network as a "perch" from which to access the White House computer systems, CNN said.
A spokesman for the White House's National Security Council played down the significance of the CNN report, calling it speculation about a previously disclosed breach.
"Any such activity is something we take very seriously. In this case, as we made clear at the time, we took immediate measures to evaluate and mitigate the activity," said spokesman Mark Stroh.
The National Security Council will not comment on CNN's "attribution to specific actors, he said.
The White House does not believe its classified systems, which contain national security information, were compromised, White House Deputy National Security Advisor Ben Rhodes told CNN in an interview.
The earlier breach of the State Department is believed to have been carried out using a phishing email targeting a State Department email account.