I'm pretty sure a quick Google would have given you the answer
There are a couple relevant points in the FAQ pertaining to licence and use of assets from example projects etc.
Unity stack answer :
http://answers.unity3d.com/questions/342714/use-of-asset-store-assests-in-commercial-game.html
"You can use any asset from the store personally and commercially, you
can edit this object by changing materials, editing the Geometry etc
You can NOT re-distribute the file, no matter how much you modify it
you can use it but not share or re-sell it.
Most of those conditions are there to prevent illegal activity or
cover the author/unity team in the case of lawsuits. As a genuine
paying user there is no need to worry about any of it, in the event
that you accidentally breach a condition (such as redistribute a
bought material on one of your models) unity will likely contact you
and ask you to remove that component rather than outright sue."