opera browser pepper data folder with strange folders and browser+pc freeze ups

at some point i had visited a website called porn.dig and it installed some folders in operas browser pepper data folder (i deleted and reinstalled opera many times) but i deleted them a while back however today i found another folder named s.ytimg.com after i restarted my pc because it got freezed alongside the browser - before i thought it was the avast update 2233 that was causing this because i had installed it the day before but now im not so sure even though there was that quick avast update 2235 so is it a malware? the windows malicious software removal tool didnt find anything after a full system scan that lasted 11 hours!!! does anyone know anything about those websites???. i even unistalled and reinstalled avast free antivirus and for several days there was nothing wrong with pc and browser. i also found a registry key called freeze.com with a subregistry named installer , how to find were it leads to , in the big window there also an id and several numbers next to it