PUP.Optional.Yontoo is the detection name for Yontoo, a large family of adware that uses different methods of browser hijacking and monetizing to get their message across. Their search applications are known to bundle “Yahoo Search.”
The bundled installer is usually different from the official one. The bundled installers require arguments for a full installation and are sometimes even aware of running on a virtual machine, both to hinder researchers.
Common infection method
Yontoo adware is usually installed by a bundler, but they do create sites and offer them as separate downloads.
Malwarebytes Anti-Malware completely removes this threat unless specifically pointed out in a dedicated removal guide.
An example of a removal guide for Search Adventure can be found on our forums.