Chrome default search engine changed to "yamdex.net" (malware)

I've just installed AdwCleaner, FRST and aswMBR. I'm attaching the scan logs. AdwCleaner and aswMBR scans have revealed an inffected file: C:\Windows\system32\drivers\netfilter2.sys (Win32:Malware-gen). I didn't fix the problem since I'd better do so under qualified help. I'm also attaching Trojan Remover log of 3 August 2015. I'm also attaching a screenshot from Chrome. My system langauge is Russian but I've provided the translation.
Thank you in advance to anyone investing time in this for...

Chrome default search engine changed to "yamdex.net" (malware)