[Peroni]

Create a stock response for candidates that are coming to you via their platform that explains they do not represent your company and that you will not review any applications that come via their platform. Include a link to your own careers page and encourage candidates to reapply there if they are genuinely interested in working for your company.

Have you tried contacting the company directly and asking them to remove your company details from their platform?

[quacksilver]

I have considered that, though I was not sure that letting a spammer know that your address is active and being read by a human was the best strategy, so thought I could make a HN thread to get suggestions / discuss how to act first.

People here seem to be relatively smart and clued up on the whole, and could suggest some things that I hadn't considered yet / create an interesting discussion for others to read.