Marketplace fraud follows a small number of patterns. Knowing them is most of the protection.
Move it off-platform
Someone asks to talk, work or pay outside Researchor. This is the most common attempt and it is always to remove your protection: no escrow, no screening, no dispute process, no record. It also breaches the Terms of Service.
Never move a transaction off-platform, whatever the reason offered.
Overpayment
A "client" sends more than agreed and asks for the difference back. The original payment is later reversed and you are out both amounts. Researchor's escrow makes this structurally difficult, which is exactly why anyone attempting it will want to leave the platform first.
Credential fraud
A profile claiming qualifications it cannot evidence. Check that publications listed actually exist and name the person. Ask about the method in your own words. Someone who did not do the work cannot explain it.
Phishing
Emails that look like Researchor asking you to sign in. We will never ask for your password by email. Check the sender domain, and reach your account by typing the address rather than following a link.
Reduce your exposure
Keep everything on-platform. Fund milestones rather than projects. Read profiles before hiring. Report anything that feels engineered.