No.1 tool for hackers

in almost all cases I’ve found where a WordPress site is hacked. This plugin is activated by the hacker. The problem is that when you delete the plugin, thinking you’ve cleaned up after the attack, the database tables for this plugin is still very present in the database causing your website to get infected again and again. This plugin probably does what it does very well, but to me, I can’t understand how it could be allowed to exist.