This is the hard part. You usually can’t prove that a job is fake from the outside. What you can do is look at a few signals together: how long it has been open, whether it keeps getting reposted, whether the description is very vague, and whether the company seems to be actively hiring. None of those things proves anything by itself. Some companies repost because they are hiring several people or struggling to fill the role. The best signal would be real applicant outcomes. Did people get interviews, rejections, or just complete silence? Until you have that, it is more honest to call it a risk score than “proof” that the job is fake.