If you want to know how to stop avast threat secured, you can follow the step given below:
1. Click the Group Policy Object you want to configure and click Edit.
2. Then go to Computer configuration.
3. Click Administrative templates.
4. Double-click Turn off enhanced notifications
5. Set the option to Enabled. Click OK.
Hopefully above steps will help you to fix the issue if not you can also follow our blog to see more on disable avast popups.