Extortionist behaviour
While claiming to be a beneficial service, the business model is more or less extortion. They are threatening publication of vulnerability details but they are not offering any useful information on the supposed vulnerability to the owner without paying up for it in advance, buying a pig in a poke. "Vulnerabilities" are mostly trivial and harmless scanning results.
This is not how bug bounties work. They are either offered voluntarily or payed out of gratitude for a meaningful hint on a serious vulnerability.
Recommendation: Ignore the mails, read the details on the supposed vulnerability after publication and then decide whether it is worth of attention. Do not pay for blackmail.








