Make it a criminal felony for everyone involved with fake job posts. It's wage theft of people who aren't even the company's employees. In almost all other contexts this would be criminal theft. Make it criminal theft in this context too. Once you include the hundreds or thousands of people they've stolen labor from, it easily passes any threshold required for it to be a felony.

Guarantee the ghost job nonsense will instantly stop once the first person is shown being shipped off to prison for a year and one day.