So about that incomplete ending....

After watching the movie, I was hoping to come and find answers about the ending. Luckily, it's not as unexplained and leaving me scratching my head like "Planet of the Apes", however, I would like to know ..... who was the bad guy?

In the middle of the movie, they record the guy's voice and match it with those of the computer company that was in that empty office space. Then when they think they found the guy, he was already dead in an accident years ago. Then when they do a close up of the bad guy's hand, it looks like a woman's?!?

Somebody fill me in please!