Malware - Kanbanier

Use Etrecheck to look for remainder pieces.

Etrecheck - the handy reporting tool for … - Apple Community

And then Devon Technology EasyFind to locate the file and show in Finder while you are in safe mode (shift key at startup). And then trash those components.

You may also find some items still in Apple menu -> System Preferences -> Users and Groups -> Select your user -> Login Items.

Post a screen shot of the files at these locations and we can tell you which files to remove to make that alert go away. There is likely more the one file causing the problem. To get to these file locations go to Finder > Go > Go to Folder, and paste each location there:

/Library/LaunchDaemons

/Library/LaunchAgents

~/Library/LaunchAgents

Please read About those "<app> will damage your computer" messages - Apple Community.