There are many tricks for other people to find out what bytes your trainer changes. The most common way is to use a trainer spy program, see my article on trainer spy programs, or a debugger such as OllyDbg.Some people will take the information from your trainer, where and what bytes are being changed, and write a trainer claiming they found the cheats themselves. Another option now is to sell trainers, as it is becoming popular, so they can even profit from your work.
If you have a problem with others stealing your work then read on.







