Browser-in-browser attacks use fake Meta Muse Ad lure to steal credentials

A phishing campaign targeting advertising managers by impersonating Gemini, Claude, ChatGPT, Perplexity, and Manus to steal credentials and multi-factor authentication (MFA) codes has added a fake Muse Ads product to its lure lineup – just eight days after Meta launched its personal AI agent.

Meta announced Muse on September 8, and by September 17, a very convincing website – museads.ai – for a product called Muse Ads that promised to help advertisers reach buyers and run sponsored placements popped up online.

“The operators already had the platform, so adapting it to a new brand can take minutes,” Oleg Zaytsev, lead security researcher at Island, told The Register.

“The striking part is how quickly they turned a timely announcement into a credible reason for someone to act.

The same platform could then be repackaged around other familiar tasks, from connecting a business tool to claiming a refund or applying for a job.” The security startup spotted the Muse Ads webpage, and upon digging into the scam uncovered that just the page was new.

“Its code, from the sign-in forms to the fake browser window, came from a wider operation that had already run fake ad products for Gemini, Claude, ChatGPT, Perplexity, and Manus,” Zaytsev and fellow Island researcher Ofek Ronen wrote in a blog post published Tuesday.

All of these products served as lures for browser-in-the-browner (BitB) attacks designed to trick agency staff, media buyers, and manager-account administrators into handing over their advertising account credentials – along with stored payment methods and client accounts – to digital thieves.

“For victims, the potential cost is loss of access to an advertising account, unauthorized ad spend, and exposure of linked client accounts,” Zaytsev told The Register.

How the scam works BitB is a clever phishing technique originally detailed by a researcher called mr.d0x in 2022.

It involves building a fake login window directly inside a legitimate one.

The fake window looks like the real thing, featuring an address bar, title, and URL, but it's just an overlay to steal users’ credentials.

According to Zaytsev, this one has likely proved very lucrative for its criminal operators, with hundreds of victim submissions to the platform, and activity still ongoing.

“From one frontend alone, we observed submissions involving roughly 200 distinct email addresses over about a month,” he told us.