A scam currently doing the rounds:-
A message from Google that you have been selected to receive one of their awards. Asks you to click on a .pdf file to see the list.
1. Google don't do awards this way
2. the .pdf probably tries to exploit weaknesses in Adobe Reader's that are not up to date ( a known issue) or might end up asking you to send money to secure your million dollar award.
Don't open it. Delete it
Do look to update your Adobe Reader (free) or better still find and download (free) and make Foxit your default pdf reader which does not have the vulnerability.