OnionClub is a Russian-language online forum presenting itself as a community and marketplace for goods, services, guides, and discussion. Its sections cover a wide range of topics, including document-related offers, payment cards and wallets, financial services, information searches, account and website hacking, and carding. The forum also hosts listings for software, online earning schemes, courses, tutorials, and proxy services, alongside general discussion and news areas.

It promotes an administration-run escrow service for transactions and provides sections for rules, seller checks, disputes, and complaints. The scraped content includes offers involving counterfeit currency, forged or questionable documents, unauthorized access, personal-data searches, and other potentially unlawful activity, as well as claims that sellers or services have been verified. These listings are user-generated and are not evidence of legitimacy, safety, or legal compliance.

Overall, OnionClub functions as a discussion forum and trading platform centered on underground online activity, with educational resources and community features alongside its marketplace