Multiple government and intelligence officials tell CBS News that an annex to the classified intelligence report on Russia’s efforts to interfere in the U.S. election contained unverified details of potentially compromising information that Russia has gathered on President-elect Donald Trump.
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U.S. intelligence is in the process of corroborating the details of what the Russians may have, but the officials tell CBS News that the former British investigator and his network is credible. Because this information is so sensitive, the annex was not part of the classified report that was distributed to a wider group of people last week.
Russian election interference and Trump's Twitter habit

A source tells CBS News it was part of the most classified report, that only would have been presented to the president, the president-elect and Gang of 8, which is compromised of the top Democrat and Republican in the House and the Senate and the chair and ranking members of the House and Senate Intelligence committees. - CBS News