They might not necessary be scam, probably their site is under maintenance or down as a result of overloading and this is not a good sign for a good project. I checked through ether scan and saw that transactions are still going on though I can’t find their history on coin market cap.

Personally, projects that look shady like this, I don’t get involved in it once my instinct tells me not to. Even if they don’t go down now, it is only a matter of time before they park up.