<quote>legitimate websites tend to get one of the top TLDs</quote> yeah. Sorry. That is unsubstantiated and by no means a good measure of trustworthyness.
I think that these kind of tests are only fit to decide if you're a coder or a monkey. As a matter of fact I think that being able to solve riddles in code is only a small part of being a developer.
I once was subjected to a hastily organised test once. I felt it was degrading and I also felt having a good conversation with a fellow developer would be much more efficient in determining what the real level of an applicant is.