Nulled and rewrapped scripts
Two different problems that get confused with each other.
Nulled
A paid script with the licence check stripped out, handed around free. The reason not to use one is not the ethics lecture, it is that the person who stripped the licence also had a reason to touch the code. Nulled investment scripts routinely ship with an extra admin account, a hardcoded payout address, or a call home that reports your install. You will be running a platform that holds other people’s money on code an anonymous stranger edited.
Also there is no support and no updates. The first security patch you miss is permanent.
Rewrapped
Legal, and more common. Somebody buys a cheap script, changes the colours and the logo, writes a new sales page, and lists it as their own product at four times the price. The software works. You are just paying a lot for a new stylesheet.
How to tell
Ask for an admin panel screenshot with their own branding in it. Rewrappers usually have front end images only, because reskinning the investor side is quick and reskinning the whole panel is not.
Ask a question that requires knowing the code. How are returns calculated on a compounding plan. What happens if the payout cron misses a day. A rewrapper gives you marketing copy back. Somebody who built it gives you a specific answer.
Reverse image search the screenshots. This takes thirty seconds and it settles it more often than you would expect.
Ask for credentials to a live install. Not a video, not a gif, a login you can click around in. investmentscript.com puts every screen of both sides on the public site and will send working admin credentials on request, which is the standard I would hold anyone to.
The cheap version of this check
If the listing will not show you the admin panel, assume there is a reason. That single rule filters out most of what is wrong with this market.