The fake whistleblower videos started popping up last fall, the work of a small but prolific Russian group that researchers call Storm-1516.

Much remains unknown about Storm-1516 — one prong of Russia’s propaganda operation — but it has produced some of the country’s most far-reaching and influential disinformation.

The Storm-1516 campaigns rely on faked primary sources that are laundered through international news sources and influencers to reach a mainstream Western audience, the group's ultimate target.

The dozens of Storm-1516 storylines examined by NBC News offer a window into the disinformation pipeline: where the most successful false claims originate and how they spread.