All I have to say to this one is: urgh. As far as I can tell, the thing is mainly ad injection malware. The c|net installer (linked) bypasses about:newaddon, but it also does other evil stuff, like disabling mixed content warnings unless the user opts out (urgh), presumably so it can display content from HTTP servers on HTTPS sites. There was a chance to opt out of search engine changes, and leaving those changes in place after uninstall, but those seemed not to change regardless. This add-on has ~5M ADU, is classified as a "Potentially Unwanted App" by Symantec, and seems to generate a large volume of complaints on support forums. ID: plugin@yontoo.com

I just sent them a message through their contact form. I'll revisit this block in 2 weeks.

They have responded and we're looking into its issues.

Also gets installed by 1ClickDownloader

(In reply to Kris Maglione [:kmag] from comment #3) > Also gets installed by 1ClickDownloader Developer claims they approached 1ClickDownloader about this and resolved the situation. Are there still instances of Yontoo being silently installed?

This is also being side-installed by the Codec Pack installer: http://www.thebestcodecpackapp.com/

Developer has been contacted.

Yontoo reports that the add-on has been removed from the Codec Pack installer. Please reopen if the problem reappears.