The 37-year-old American woman had never been to Russia and even faked an accent when hosting her pro-Kremlin podcast series.
To her followers, the person behind the social media account called “Donbas Devushka” - or Donbas Girl - is a Russian woman from the occupied city of Luhansk.
She has actively spread disinformation about the war in Ukraine since its start in February 2022.
But in reality, the person behind the pro-Kremlin account turned out to be a 37-year old American woman called Sarah Bils.
Bils is a former non-commissioned officer with the US Navy who was recently released from active duty and based in the state of Washington.
She was first exposed by pro-Ukrainian open source intelligence activists known as NAFO.
Sarah Bils built up a social media following of more than 135,000 people on Twitter, Telegram and YouTube.
She raised money for the Russian cause and mocked the death of Ukrainian soldiers on her accounts.
On social media, Donbass Devushka posted photos of herself, claiming her name was Mila Medvedev and spoke with a forced Russian accent during her podcasts.
Bils also played a key role in disseminating the recently leaked Pentagon documents, according to the Wall Street Journal.
US Air National Guard technician Jack Teixeira was charged on Friday with taking and transmitting the classified papers – he now faces 15 years in prison.
Sarah Bils, who had secret security clearances while serving, told the Wall Street Journal she did not help to leak the documents.
However, screenshots have circulated from her Telegram account which shows the leaked files.
The Journal also noted the documents posted on her channel were altered versions of the originals, which edited the number of deaths to make it look like Russia was losing less than it really was.
Sarah Bils admitted to the Journal she was the administrator of Donbas Devushka accounts and host of the podcasts.
But she said she wasn’t alone and that there were 15 people involved in running the network around the world.