Hackers posted documents online that appear to reveal detailed information on the movements of First Lady Michelle Obama, Vice President Joe Biden and Democratic presidential nominee Hillary Clinton.
The Department of Justice is "looking into" the authenticity of the documents, US Attorney General Loretta Lynch said during a press conference. They're thought to have come from the breached personal Gmail account of a low-level part-time contractor at the White House hired to aid in travel logistics.
The documents, posted Thursday, include information on the hotel room used by Biden during a July trip to Los Angeles, the hallways and motorcade route used by Clinton during a visit to a conference last year, and a scan of Michelle Obama's passport, CBS News reported.
The documents were posted on DCLeaks.com, the same site on which emails from former Secretary of State Colin Powell appeared last week.
The hack is the latest to raise questions about the security of emails and other documents pertaining to US politicians. In June, the Democratic National Committee revealed it had been hacked. A White House computer network, a US State Department system, and a network at the Pentagon have also been breached.
It's not clear if the White House staffer's use of a personal email account broke government rules, because he was a contractor, CBS News said.
"Our recommendation to White House staffers and to employees of the federal government is that they should use their official government email for official government business," White House Press Secretary Josh Earnest said yesterday during a press conference.
Earnest said the White House is taking a "close look" at the leaks and that it had no comment about who might have been behind the hack.