Drew this enemy card...
http://hallofbeorn.com/LotR/Details/Hobgoblin-TWoR
And the card from the top of my deck was a trap. Is it considered attached to him as a trap? Or I have to defeat him first, then I can play it later as a trap?
The Nameless Thing issue remains in the FAQ:
So by analogy, I'd guess that the answer to the OP question is, the trap's text is not active (essentially what @Alonewolf87 said).