WordPress site has been hacked by insiderz crew

Sorry to hear that – these will help you deal with that:

https://codex.www.ads-software.com/FAQ_My_site_was_hacked
https://www.ads-software.com/support/topic/268083#post-1065779
https://smackdown.blogsblogsblogs.com/2008/06/24/how-to-completely-clean-your-hacked-wordpress-installation/
https://ottopress.com/2009/hacked-wordpress-backdoors/

Additional Resources:
https://sitecheck.sucuri.net/scanner/
https://www.unmaskparasites.com/
https://blog.sucuri.net/2012/03/wordpress-understanding-its-true-vulnerability.html

Remove ALL WP-files, themes and plugins. Reinstall from fresh core files. Change mysql user / password, add new salt code, change your login password to something very strong. You should also consider changing your ftp password and check your computer for virus, trojans and malware.
Then, hopefully, if not the hacker has added something nasty in your DB, you have a fresh start.