Executables modified by third parties can easily steal your browser cookies, saved passwords, and banking information.
The "Merry Christmas" event is a built-in free update. You do not need a special mod or crack to access it. Players can permanently toggle the Christmas event or unlock its "Freezer" weapon skin by starting a New Game+ run and activating it in the perks menu. Serious Sam: Siberian Mayhem - Merry Christmas Update 1.06
Refers to the official seasonal Update 1.06 released by the game developers.