I guess I watched this movie sometime between 2005-2007 but cant be sure. I remember only a few scenes. They go like this:

A boy and his family moves to a new apartment in a building and the boy and his friend they find a briefcase full of money and they live a dangerous adventure (I cant be sure but I guess ex-owner of the house and some criminals that are after him)

The movie ends with a happy ending. In the last scene the family moves to a detached suburban house and the family gives the attic to their son and he is surprised and happy and his friend makes a joke, its something like "what is that bag??"

Thanks already, any help would be appreciated.

Angels in the Attic (2001) ?

From IMDb review:
A heartwarming story about two kids who find a bank robber's loot in the attic of their apartment block. Instead of telling someone or spending it on themselves (like I suppose most kids would), they go around buying presents for their neighbors, whether they are needy or because they've lost something they loved. When the robber discovers they have taken his loot, he gives them an ultimatum: Return the money or else.

Angels in the Attic (2001) - IMDb (http://www.imdb.com/title/tt0135774/)

Yes MystMoonstruck, this was it. Thanks a lot. Appreciated :)

Yes MystMoonstruck, this was it. Thanks a lot. Appreciated :)

You're welcome!

You also might enjoy this similar film:
Millions (2004)
https://en.wikipedia.org/wiki/Millions_(2004_film)