Trump is not identified by name in the House phone records, but investigators said they suspect he may be a person with a blocked number listed as “-1” in the files. And administration officials said separately that Trump has communicated regularly with Giuliani on unsecured lines.

“It happened all the time,” said one former senior aide, who noted that Giuliani had a range of foreign clients…

Insight into Giuliani’s discussions with Trump could enable Moscow to adapt or amplify its propaganda promoting the baseless claim that Ukraine, rather than Russia, hacked the Democratic National Committee in the 2016 U.S. election. That claim is now widely embraced by Trump’s Republican allies. Russia is already using its disinformation capabilities to target U.S. citizens, officials said, and could enlist its own operatives in Ukraine to feed false information to Giuliani, who traveled to Kyiv this week. He met there with a Ukrainian lawmaker who studied at the KGB’s academy in Moscow in the early 1990s…

Trump and Giuliani have effectively “given the Russians ammunition they can use in an overt fashion, a covert fashion or in the twisting of information,” said John Sipher, former deputy chief of Russia operations at the CIA. Sipher and others said that it is so likely that Russia tracked the calls of Giuliani and others that the Kremlin probably knows more now about those conversations than impeachment investigators.