How did you restore the file?
Open the Bitdefender Desktop Application.
Select the Bell-Icon with the Red Notifications Indicator
Search the Notifications for the Infected File alert
Unfold the message to reveal 2 buttons: Delete or Restore
If the File is Restored during the installation process it should just finish with the installation.
If this did not work you should now - after Restoring the file - be able to repair the installation through the GOG Galaxy Client.
Since I have no official statement that this file is safe I will wait a bit until I execute it.
Better safe than sorry.
Our games are thoroughly checked for viruses before launch. Therefore we are confident that any warning your software displays is just a “false positive”.
This happens when an anti-virus/anti-malware heuristic scanner (or “smart scanner”) checks a file and finds parts of code that resemble a virus. Please disregard this warning, or use www.virustotal.com to have the file scanned by 30+ known, well-established anti-virus scanners. If the results are inconsistent (as in, different scanners show different results), this practically proves that it's a false positive.