Transcript for A look inside a Russian 'troll factory'

closer look at one of the Russian entities accused of meddling in the U.S. Election. I recently traveled to St. Petersburg, Russia and it's safe to say they were not happy to see me. So much attention paid to what's allegedly happening inside this building. We want to go and see if we can find out for ourselves. What's allegedly happening here, the manufacture of fake news. This is a so-called troll factory. I'm from ABC news in the United States. Off from here. Turn off the camera. We barely make it past the front door. We'll leave. We'll leave. Reporter: This is the E epicenter of Russia's propaganda war. Something they clearly do not want us to. Inside we're told dozens of internet trolls are endeavoring to exploit America's division. These are just some of the thousands of ads they posted online during the 2016 presidential campaign which reached more than 150 million Americans on Facebook alone. We didn't make it inside. Where are we? Reporter: But we're now on our way to meet someone who says she did. She wins outhere. Reporter: She is a journalist who went undercover in 2015 working at the factory for about $700 a0 month. She says she and some other ex-trolls shot these undercover videos inside the building showing tight security and rows of trolls typing away. So what was your job when you were working there? Translator: I was placed into an elite department. Reporter: Her job would include inventing characters and topics carefully selected by her boss, the U.S. Always at the top of the list. Translator: These characters were carefully crafted to transmit the Kremlin's thoughts to the public. Reporter: Interesting that ex-troll ludiomil Ya sav chuck said she and her family have faced threats but remains dedicated to her mission which is shutting the troll factory down and described their work to us as murder through words. And I would imagine she fears for her life and she's not going incognito so they know what she looks like. All the other ex-trolls we heard from left the country. Not her. I have not seen anything like that before. It's an interesting country to say the least. More to come.

This transcript has been automatically generated and may not be 100% accurate.