Smeg! I hate hackers. If by some odd reason, you are here because you think I hack; my best advice is that you make sure your router is set up properly for online gaming. Your in game NAT needs to be "OPEN" for relatively lag free gaming. At the minimum : your router address should be something like this http://192.168.1.1 just copy and paste into your browser then find where your router stores your NAT/PAT settings they are usually in the advanced section of the http interface.
TCP: UDP (Both) 3478
TCP: UDP (Both) 4379:4380
TCP: UDP (Both) 27000:27050
These are the Steam client address and you should do an internet search to confirm that they are current.

In the pull down menu you should have something like "create new rule" then name it something like "Steam" and just add the numbers in external and internal ports, then the protocol TCP or UDP, then to what computer on your network should use them, you should now be OPEN. Caution with the DMZ settings.