Suddenly, menu bar applications have blue badges I am using a MacBook Air 13' bought in 2017, running Mojave 10.14.1 (18B75). I recently removed malware and plugins named Weknow.ac. Now, several of the application badges and indicators in the menu bar appear with a blue background. I've tried different things to remove the background color, mainly by upgrading and re-installing the apps affected, but nothing seems to work. Any help would be much appreciated.

Examples include;

NTFS for Mac (gear icon on the top right corner)



Google BackUp And Sync (three dots on the top right corner)



CleanMyMac X (local storage disk drive icon on the top left corner)
I see the same thing for Google Drive. Blue around the dots. I don't think this is a problem with your system, more that the highlight color selected in Preferences is being added to a menu item because of the way the company coded the app. Some apps are great at integrating (e.g. Dropbox, which went to great lengths to get a custom sidebar icon) and others are not (e.g. Google, which has weird bugs like this in the display of some apps).