Sure, I am 'aware' of them, but believing in it is another question. There's no documents or anything concerning this situation. These "spiritual messages" people are getting from them has been going around for more than 60 years, and they were supposed to visit since the 70s if I recall correctly. Although I would love to think its real, and I'm not crossing out that option, I'm just more of a realist and I search for other answers from information that we physically have, as much as I would love to work with aliens for the best of humanity.
On a side note: you mentioned Nibiru, and mentioned it with natural disasters, so I'm assuming you're mentioning the planet that can come collide with earth (or other claims that are made from it). It's something that was made up by some woman that already twice changed the date on her website on when it's supposed to arrive (and now saying it falls under 2012 -- oh.. what a coincidence =P). And historically, if it really is supposedly an alien message, I'm sure they would use a different name for the planet, since Nibiru means Jupiter from ancient Byzantine.
All-in-all from my honest opinion, its alright and fun to read about these things, but don't let them brainwash you.