Yahoo search malware in address bar

There are two totally unnecessary and potentially dangerous software apps that you've installed: Avira and CleanMyMac. Most of the experienced contributors to these forums consider CMM to be akin to malware. There is no reason to ever install or run any 3rd party "cleaning", "optimizing", "speed-up", anti-virus or security apps on your Mac.  This user tip describes what you need to know and do to protect your Mac: Effective defenses against malware and other threats - Apple Community   

Uninstall both according to the developer's instructions. When done you can check to see if you've removed all of the supporting files by downloading and running Find Any File to search for any files with the application's name  and the developer's name in the file name.  For example for those two you'd do the following searches: 

1 - Name contains cleanmymac

2 - Names contains macpaw

3 - Name contains avira

Any files that are found can be dragged from the search results window to the Desktop or Trash bin in the Dock for deletion.

FAF can search areas that Spotlight can't like invisible folders, system folders and packages.  

As for the adware that is affecting Chrome download and run the free version of Malwarebytes. It was developed by a long time contributor to these forums and a highly respected member of the computer security community. It is an excellent app and safe to use and have.

Ensure you have complete and current backups.

Remove the anti-malware (malwarebytes, avira), remove both of the VPN client apps if you’re nor using those to connect to a private network, remove the cleaner app, remove what looks to be some adware, reboot, and try again.

Some of these apps can be problematic to remove, and these can sometimes leave corruptions. That can mean backups, wiping, reloading macOS, and using Migration Assistant to reload your files and documents and preferences, and re-installing the necessary apps from known-good copies.

If you’re not specifically using these apps, remove Microsoft Silverlight as that’s long gone and unsupported, and remove Adobe Flash Player as that’s going away soon.

If you don’t specifically need Oracle Java, remove that.

Lots of plugins. How many of those do you need?

Please download and enable full device access for and then run (free) EtreCheck. Then open a new reply here and then press the button that looks like a printed page to get a text input box big enough to paste the hardware and software configuration report here. That’ll provide an inventory of what’s installed.

Locate that folder and check to see what the permissions for it are. Set it to Read & Write for everyone, you, the admin and all items listed. Then try deleting.

You might have to reinstall CMM in order to use its built-in removal function. Look into that.