This January, as Mark Zuckerberg was embarking on his quest to “fix” Facebook, one writer proposed a bold idea: make Facebook more like Instagram, “the Facebook-owned app that isn’t destabilizing society”. Instagram was no panacea, according to the New York Times tech columnist, but the downsides of the largely visual network – making “some of its users feel ugly and unpopular” – were insignificant compared with those of a highly politicized Facebook that could “undermine democracies and promote misinformation around the world”.

The idea that Instagram was a safe harbor for social media users in a sea of propaganda and political divisiveness caught on, both among users who didn’t realize the app was owned by scandal-ridden Facebook and with the tech press. An April Bloomberg Businessweek cover story framed Instagram as “Facebook’s best hope” and “Mark Zuckerberg’s way out of the latest data scandal”.

Even Elon Musk, who publicly ordered the deletion of Tesla’s and SpaceX’s Facebook pages amid the #DeleteFacebook Cambridge Analytica backlash, stamped Instagram with his imprimatur, tweeting that it was “probably OK” in his opinion, “so long as it stays fairly independent”.

But two new analyses of the Russian online propaganda campaign by the Internet Research Agency reveal that this view of Instagram was as rose-colored as, well, an artistically filtered Instagram post.

“Instagram was perhaps the most effective platform for the Internet Research Agency,” states the report by New Knowledge, an American cybersecurity firm which analyzed data sets from Facebook, YouTube and Twitter.

During the period studied by the report’s authors, IRA posts on Instagram garnered more than twice as many engagements (such as likes or comments) as IRA posts on Facebook – 187m on Instagram vs 77m on Facebook – despite the fact that Facebook offers many more ways for users to interact with content, and Instagram has no native “sharing” button to promote virality.

And as public awareness of inauthentic behavior on Facebook and Twitter increased in 2017, the IRA increased its activity on Instagram. In the six months following the US presidential election, the IRA’s activity on Facebook, Twitter and YouTube climbed (by between 45-84%), while activity on Instagram soared (by 238%), according to the second analysis, by researchers at the University of Oxford.

The IRA created dozens of Instagram accounts, each with a particular identity. The most successful, including @blackstagram_, @american.veterans, and @rainbow_nation_us had more than 100,000 followers apiece.

Like traditional Instagram influencers, these accounts were selling something, in some cases literally. Several of the accounts engaged in merchandising, according to New Knowledge, selling T-shirts, as well as “LGBT-positive sex toys and many variants of triptych and 5-panel artwork featuring traditionally conservative, patriotic themes”. The report suggests that selling products might have been a honey pot to extract more information – such as mailing addresses or phone numbers – from users.

While it’s impossible to pinpoint the effect these accounts may have had on the public, or on the election, it’s also impossible to ignore Instagram’s power to persuade. There’s a reason “Instagram influencer” is an actual career now.

Whether Facebook is prepared to confront this vulnerability is an open question. Since admitting that its platform was hijacked by the IRA, Facebook’s responses have largely glossed over Instagram. The platform was named only three times in the prepared testimony of Facebook’s general counsel, Colin Stretch, when he testified about the influence operation before the Senate in October 2017 – and never in a way that addressed the features of Instagram that distinguish it from Facebook.

Asked whether the company has plans to address propaganda on Instagram specifically, a Facebook spokesperson pointed to three previous blogposts on Russian propaganda that do not include any specific discussion of Instagram.

“Alongside Facebook, we’re continuously working to prevent election interference on Instagram,” an Instagram spokeswoman, Stephanie Noon, said in a statement. “We’ve repeatedly shared action we’ve taken against the IRA and other bad actors who are attempting to interfere with elections on the platform. It’s important to us that people trust the interactions they have on Instagram, and that’s why we’ll continue to focus on this area.”

If the company does attempt to address the particular vulnerabilities of Instagram, the team tasked with fixing it will be Facebook – not Instagram – grown. In September, Instagram cofounders Kevin Systrom and Mike Krieger quit amid suspected conflicts with Mark Zuckerberg. Instagram is now led by Adam Mosseri, a longtime Facebook executive who was previously in charge of Facebook’s News Feed.