as you can see many br servers are offline at now, just check the rank and you'll see. so we have concluded that attackers seem to be using GameTracker to get IPs of game servers.

you can confirm that?

There is no way that we can determine that GameTracker is being used to get IPs. There are quite a few game server tracking services and master server lists that list servers, so there is absolutely no way that GameTracker could help with this even if it was related to us as you claim.