Need some help.

1 Get a free antivirus from Google play store

2 Remove unwanted Apps from your Tablet ( it may came from one of those App )

3 Turn off automatic updates , it will only slow your tablet speed

4 Use a good browser to avoid going to the harmful websites

5 Save your tablet data on your laptop or computer and then format your tablet

6 Helperbar virus came from on of your browser , its a kind of extension , uninstall your browsers and unwanted app .