In both cases, the fraud was easily made plain when I asked details about their work history. In one case, they claimed to live in the same metro area I had previously lived for 18 years, but couldn’t answer any basic questions about the place. In another situation, they claimed a workplace that was in a community I was familiar with and that was far too small to have corporate headquarters of any type I wouldn’t be familiar with.
After 5-10 minutes of probing, both candidates bailed on the interview realizing they were wasting their time.
They also exhibited some of the other signs as described at the link - no employment profiles on LinkedIn or just a basic profile, names that didn’t match their ethnicity, etc.
I have no evidence or intuition to conclude they were North Korean, as employment fraud is certainly not limited to North Korea. I can’t imagine either of the candidates I spoke to surviving even casual scrutiny, so I highly doubt this kind of fraud results in much success.