It goes without saying (I hope) that this is fake and malicious and that users should never open file attached from someone they don't personally know and expect an attachment from. If this attachment is run it installs a trojan on the user's computer.
The e-mail looks like this:
Dear Facebook user,
Due to Facebook policy changes, all Facebook users must submit a new, updated account agreement, regardless of their original account start date.
Accounts that do not submit the updated account agreement by the deadline will have restricted.
Please unzip the attached file and run “agreement.exe” by double-clicking it.
The Facebook Team
Thanks to the Sophos Labs blog for this valuable information.