What version of the game is he using?
Do you know of others who have tested the same version?
Are there people who have since downloaded the version without problems?
The fact it goes to a DB site is a bit odd and makes me think it's not something already on his PC, more likely someone got into your site and planted the link. I'm no expert on the subject though so I could be totally wrong!
Have you since downloaded the game yourself?
What is the polish website?
TGC Forum - converting error messages into sarcasm since 2002.