Does anyone remember the name of this movie?

It was futuristic and took place entirely inside an apartment building that looked like an old hotel. The main character was too paranoid to leave his room. The only person he trusted was a delivery guy who ended up infecting him with a nanovirus that turned him into a walking commercial for a few particular products. There may have been a girl who lived in the apartment building who tried to help him, but he was too paranoid to trust her. I think it came out between 2002 and 2006. It might have been billed as "noir". I want to say the name of movie was the name of the nanobug that eventually left our hero completely out of control of his mind and randomly saying things that promoted certain products. I think those were the only three characters in the film.