Are you a victim to spammer attacks? This plugin will help you delete all pending comments with one simple click.
Note: this plugin is 3 years old but still works perfectly fine.
First log into your WordPress dashboard and go to Plugins > Add New. Then type in Delete Pending Comments and select Install Now.
The activate the plugin and you will be able to find it under Comments > Delete Pending Comments.
You will then need to copy or type in the sentence ‘I am sure I want to delete all pending comments and realize this can’t be undone’ and select Delete Pending Comments and all pending comments will be deleted from your website.