In May, several French and German social media influencers received a strange proposal.

A London-based public relations agency wanted to pay them to promote messages on behalf of a client. A polished three-page document detailed what to say and on which platforms to say it.

But it asked the influencers to push not beauty products or vacation packages, as is typical, but falsehoods tarring Pfizer-BioNTech’s Covid-19 vaccine. Stranger still, the agency, Fazze, claimed a London address where there is no evidence any such company exists.

Some recipients posted screenshots of the offer. Exposed, Fazze scrubbed its social media accounts. That same week, Brazilian and Indian influencers posted videos echoing Fazze’s script to hundreds of thousands of viewers.

The scheme appears to be part of a secretive industry that security analysts and American officials say is exploding in scale: disinformation for hire.

Private firms, straddling traditional marketing and the shadow world of geopolitical influence operations, are […]