Ok, you will find many websites like this one who will give you all the information about how to stay away from that assignment, or whether that particular website is a hoax, or whether this job opportunity exists and is as financially lucrative as expressed, but all of us are unable to give you one kind of service, unless we want to spend a lifetime in litigation - we cannot tell you whether this particular person is a hoax or not, unless it happens to me myself. 

Therefore, the best that we can do is train you how to find out whether the freelance assignment you got is a fake or not. Here is one simple rule that you should live by while on the online world:

You can actually use Google, or any other strong search engine like Google to find out whether you are dealing with a scammer, be it a site or an individual.  Here is you can do it. 

Whenever you come across a site that seems scammy, just go to Google and type 'nameofsite+is+scam.' Once you do this, you will come across the search results. If you do find some search results for this term, you can be sure that at least someone has had the same allegations or doubts as you do. If you do not find any results, well, it may be a genuine thing or it might be a scam that has not been unearthed yet. It's all about how pessimistic or optimistic you are. 

This method might not be much useful if you are looking for a particular person or an Account name, simply because Account Names are dispensible and a person might be able to change their account names within hours.