Updater.bak, a part of the Yontoo adware, is a web browser plugin that affords to cause multifarious and abundant pup-ups, banners, and links in your browsers. As a result, created by Dragon Branch, Updater.bak is also considered as a vicious adware which has been attested by 28 anti-malware scanners.
I f you want to get more information about it, you read the post Effective Methods to Remove Updater.bak from Your Windows (Removal Guide) in virusremovalexpert.blogspot.com.