Yeah, I had to use a CNET installer to install some program and along with it, it forced me to install this phising search engine called Blekko Toolbar that took over my browser (I say it forced me because I unchecked "I agree" and continued but it still installed anyways) and now I pretty much hate CNET.
The only way I know how to fix it is to get Malwarebytes Anti-Malware, run a quick scan of your hard drive, and delete all bad files found. When I scanned my comp, I found a lot of virus files embedded deep in my user cache and I removed them all. Then I downloaded Chrome's Website Blocker app, blocked Blekko, set Google back as my search engine, and now I'm good to go. The only trace left is that it still attempts to open a Blekko tab once Chrome starts, only to be cut off by the blocker app while loading.