Help needed, my server has been detected for spoofed bingbot attack against WP

My shared hosting server has been detected for doing spoofed bingbot attack against WordPress, similar to http://boomshadow.net/tech/fixes/spoofed-bingbot/ , but as the attacker, not the victim.

How do I clean my server so it stop doing these brute force attack? So far I've run rkhunter and clamav. Is there anything else I should do? My server is using CloudLinux + WHM/cPanel.