I also have this problem, when I startup the pc, after some random minutes, a Chrome page pop up redirected first to Gangnamgame.org (you could easily see that by closing your internet connection) and then immediately redirect to dota2game.org.
I've tried this softwares:
Malwarebytes
Combofix
AdwCleaner
HitmanPro
JRT
Spybot
UltraAdwareKiller
RKill
SpyHunter 4
Microsoft Security Essentials
But no one worked, I keep getting this problem, I don't want to format my hard disk but I don't know waht to do