Thus GTA4 was released this week on pc there is quite few nr of web pages offering and/or rating the game , i found quite few with not so legimate add's and/or downloads for free/or cracked copy of the game , so as one of the gamers my self tought will give out small time alarm , nothing comes free and you risk with more then few hrs download time .
Edit: Might only be me but i noticed increased amount of Virtumonde infections in last two weeks , just my personal tought about this wild fire , they might have connection (or not).