GWT malware warning for my website and defaced

To prevent re-infection I would do the following:

1.Change all passwords (cPanel/Wordpress/FTP/database) to strong 15 character number/letter/symbol versions.
2. Update your salt keys in the wp-config.php file to log out all existing users.
3. Delete any new unknown users.
4. Install Ninja Firewall and use the file guard and file check features to keep an eye on your site files over the next week or so.
5. Install Wordfence and keep an eye on the results of the daily site scans.
6. Follow the advice in the codex to harden your WordPress installation:
https://codex.www.ads-software.com/Hardening_WordPress

I had the same thing happen! So frustrating! Did you get it fixed?

See the resources linked above and these too:

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

Thanks Barnez and WPyogi
I used my previous backup and restored to it.
removed all wordpress files and database.
Other way is to go through all the files and scan them for changes hacker made and removed selective files and code but it is time taking.