Of course. But that's what were discussing here right, ways people might commit fraud. If people can popup businesses for fake, fraudulent jobs, I wouldn't think this kind of fraud is out for them either. And in some jurisdictions, being hard to trace as a business beneficiary is actually not difficult.

It surprised me when I ran a small business my bank didn't even require me to file the signatures up front. I just typed in peoples IBAN, the amount, and got it. They never asked for paperwork ever. Naturally, I didn't commit a crime, but I'm surprised with the trust.

So, yes, keep your IBAN secret, it can be enough for someone with criminal intent.