The firm became embroiled in scandal in March when former analyst, 28-year-old Canadian Christopher Wylie, revealed it had used a Facebook personality prediction app to hijack up to 87 million Facebook users' data - claims it denies.
Bannon's attorney William Burck did not immediately respond to an email request for comment on Wylie's testimony.
The whistle-blower who revealed how Cambridge Analytica harvested Facebook Inc. user data to target election ads said the company could have shared that information with Russian Federation.
The company, which did work for President Donald Trump's 2016 campaign, had stated earlier this month that it had lost "virtually all" customers and suppliers as a result of reports that it improperly obtained information from tens of millions of Facebook users.
Bannon worked on Trump's campaign and became a White House aide when Trump took office in January 2017.
Few months ago Wylie made headlines for revealing almost 87 million people may have been victims of data harvested by Cambridge Analytica without their consent as a result of a third-party application spoke of voter suppression during a Senate Intelligence Committee Wednesday.
Meanwhile, another whistleblower said Britons' personal data may have been misused by a pro-Brexit campaign ahead of the 2016 referendum in which Britain voted to leave the European Union.
"The company learned that there were segments of the population that responded to messages like "drain the swamp" or images of border walls or indeed paranoia about the "deep state" that weren't necessarily reflected in mainstream polling or mainstream political discourse that Steve Bannon was interested in to help build his movement", Wylie said.
"Wylie told the panel that Russian-American researcher Aleksandr Kogan, who created an application to harvest Facebook user profile data, was working at the same time on Russian-funded projects, including "behavioral research".