I have opened a program from a website, has my MBP been infected with a virus?

I have opened a file on http://ift.tt/1CN5NwI. I was supposed to click on a torrent file but I clicked on the big DOWNLOAD link.

And I had no idea that I was not supposed to open a dmg file. Anyway, done is done. I opened it, and there was an install file, I double clicked on it. Then I was not asked to do anything, it just directed me to a website.

How do I make sure I do not have a virus or spyware? Running AIR'13 Yosemite. The file name was macfest. The content looks like this:

I also used Sophos Anti-virus and it detected OSX/FkCodec-A in the dmg file that I trashed.