Microsoft President Brad Smith warned the danger of foreign interference in the U.S. election will surge in the final two days of the presidential campaign.

"The most perilous moment will come, I think, 48 hours before the election,” Smith told the Senate Intelligence Committee on Wednesday.

Smith said that was the "lesson to be learned” from the Slovakian election last fall, in which fake audio of one of the top candidates circulated online days before the election.