The supposed problem is being peddled by a company called Socure, who, coincidentally, offer the solution to this problem. There are absolutely "fake" remote workers floating around but to suppose this is some grand security-focused North Korean government conspiracy rather than people from poorer nations trying to get paid is without evidence. "North Korean" job applicants has become a meme, any suspicious looking applicant is being labelled "North Korean" by people who've read articles planted by Socure. If this were a grand North Korean government orchestrated conspiracy we would not see hundreds of job applicants engaging in exactly the same strategy for the same job.
https://www.socure.com/blog/hiring-the-enemy-employment-frau...