The Democratic National Committee contacted the FBI on Tuesday after it detected what it believes was the beginning of a sophisticated attempt to hack into its voter database, a Democratic source tells CNN.
The DNC was alerted in the early hours of Tuesday morning by a cloud service provider and a security research firm that a fake login page had been created in an attempt to gather usernames and passwords that would allow access to the party's database, the source said.
The page was designed to look like the access page Democratic Party officials and campaigns across the country use to log into a service called Votebuilder, which hosts the database, the source said, adding the DNC believed it was designed to trick people into handing over their login details.
The source said the DNC is investigating who may have been responsible for the attempted attack, but that it has no reason to believe its voter file was accessed or altered.
The DNC's chief security officer Bob Lord, a former Yahoo! executive, briefed Democrats on the attempted attack at a meeting of the Association of State Democratic Committees in Chicago on Wednesday.
CNN has reached out to the FBI for comment.
Early Tuesday morning, Microsoft announced that parts of an operation linked to Russian military intelligence targeting the US Senate and conservative think tanks that advocated for tougher policies against Russia were thwarted last week.
That disclosure, coming less than three months ahead of the 2018 midterms, demonstrated Russia's continued efforts to destabilize US institutions. The news also places additional pressure on President Donald Trump to take action, even though he downplayed Russia's involvement as recently as Monday.
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