When Instagram users searched for Representative Cheri Bustos in July, they encountered two accounts featuring identical images of the congresswoman holding a small goat.

One, “cheribustos,” was her official campaign account. The other, “bustoscherie,” was a fake claiming to be Bustos, a Democrat from Illinois. It was one of dozens that party officials have seen impersonating candidates and campaign staff on Instagram, its parent company Facebook Inc. and Twitter Inc. in the lead up to November’s elections.

“Bustoscherie” was discovered before it began posting, but political strategists fear accounts like it are a sign that malicious actors -- whether U.S. adversaries or domestic players -- are putting down markers on social media that could be activated to spread false information as the election nears.

“We see it as a threat to everyone who is running for office this year,” said Ben Block, the digital rapid response director at the Democratic Congressional Campaign Committee, who leads a team that found social media pages impersonating Democrats ranging from prominent incumbent members of Congress to little-known challengers. The fakes “in every way, shape and form” mimic the real candidates, and they have disproportionately targeted women -- particularly women of color -- running for office this cycle, he said.

Impostor accounts on social media aren’t new for political candidates, but they are being detected at a higher rate than in previous years, Block said. The increase may be partly due to additional investment by Democrats in finding disinformation following a Russian social media campaign that sought to sow discord and help then-candidate Donald Trump in the last presidential election.

Republican Party officials didn’t respond to questions about whether its candidates were being impersonated online too. But Republican candidates have been targeted in the past, and a Facebook spokesperson said fake accounts are mimicking candidates of both parties in the current election cycle.

It’s not clear who is behind the current batch of phony accounts nor what their motives might be. Besides spreading false information, they can be used for various scams, including extortion or hacking user accounts. Foreign actors could play a role and were believed to be behind fake accounts promoting Iranian interests that purported to be Republican congressional candidates Marla Livengood and Jineea Butler ahead of the 2018 election.

That year, a Russia-based information operation also created a Twitter page that claimed to be Senator Marco Rubio, posting the false claim that British intelligence spied on Trump and intended to support Democrats. Rubio described the account as “child’s play compared to what they plan to do in the future” and has since called for a stronger U.S. stance on foreign election interference.

A March report from New York University’s Brennan Center for Justice found that Russian trolls have “gotten better at impersonating candidates and parties.”

Kevin McAlister, a Facebook spokesman, said such accounts were against company policies, and that teams and technology were used to find and remove them. “We have made several improvements to better combat impersonation — including new detection technology to spot scams, more specific reporting options, and more people working on this issue,” he said.

A Twitter representative said that impersonation is banned on the platform, with the exception of parody accounts which are governed by strict rules, a Twitter representative said. Yet, fake ones continue to pop up: For example, Twitter confirmed in recent weeks that it suspended pages claiming to be family members of candidates -- of both parties -- at the top of the 2020 ticket.

Facebook and Twitter have created various tools to help protect candidates from impostors, such as badges that can be added to their verified accounts. But Block’s team conducted an audit and found dozens of 2020 candidates that hadn’t been verified or marked with the election badge.

In a statement, Bustos, who is also chair of the DCCC, said social media platforms “need to acknowledge the influence they have in our elections and step up to implement reforms that prevent further damage to our democracy.” Like her, the Democratic National Committee and Biden campaign have also urged social media companies to take more proactive stances on disinformation -- rather than placing the burden on others to find and report it. Aside from Bustos, none of the other Democrats who were targeted by impostors were willing to talk publicly about it, Block said.

Block’s team found the account impersonating Bustos on July 22 and notified Instagram. It was removed by the end of the day, but Instagram wouldn’t provide any information about who was behind it or when it was created, Block said.

The motives behind fake candidate accounts aren’t always tied to politics. For example, Adam Kinzinger, the Republican congressman from Illinois, has been targeted by impersonators as part of romance scams and other financial fraud attempts that appear to be related to a broader plot to impersonate service members. Maura Gillespie, Kinzinger’s communications director, said she flags approximately five such accounts each month to the platforms, which remove them. In the last year, she has also reported fake Instagram pages pretending to be the former Republican officials Nikki Haley and Dana Perino after the accounts directly messaged her.

In the 2020 election cycle, campaign staffers have also been impersonated frequently, according to Jiore Craig, vice president of the Democratic polling firm GQR, where she advises candidates on dealing with disinformation. Often these accounts, and dozens of others GQR has seen impersonating candidates, appeared to be for the purpose of spreading political disinformation, Craig said. She declined to identify the fake accounts.

Craig has observed these accounts deploying tactics to “blend in” and appear trustworthy on social media. For example, one impersonator sent friend requests to the real candidate’s family members on Facebook. Impersonators also try to avoid scrutiny by posting mundane content before transitioning to “more nefarious” messaging.

The problem has become so pervasive that Craig’s company has added a training session to warn campaigns about the ways impersonation accounts can create disinformation, she said.