Russian hackers may have obtained files from Hillary Clinton and top aide Sidney Blumenthal by hacking Guccifer, the Romanian man who first breached Clinton’s private server, according to sources involved with House and Senate intelligence committees quoted in PJMedia.

Committee aides indicated the files might be publicly available on the “dark web,” which is accessible through Internet browsers like Tor that mask a user’s IP address. The documents would include both classified and unclassified information Clinton held on her homebrew network when Guccifer was active, prior to his arrest in January 2014.