A 1KB file, with Google listed as the developer, and absolutely no description of what it is suppose to unlock? I would have guessed a virus, but the rar files contains a Content_Unlocker.xml file, containing what looks like a serial number. A Google search on that number found a non-English forum topic implying it unlocks an armour set and weapon (with a screenshot matching Gamestop's Blood Echelon armour/weapon Xbox pre-order bonus).
The only bonus content that I am aware of so far has been equipment sets or items.
