Hacker and the scammer are only normal in this kind of job or in this kind of world because hackers and scammers have one only goals. They steal your earnings or profit just to have it. They do anything just to steal your money. And there are ways how to  prevent it. For hackers make sure that your password is really strong consist of uppercase and lowercase letters and numbers you may use a symbol too if you want and don't click for the untrastable link. For the scammer. Just do research in your buyer or seller