WP 3.5 got hacked !

Will somebody address these issues like ASAP ! ?

Sure! Here’s a list of articles that explains what you need to do.

You need to start working your way through these resources:
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
https://codex.www.ads-software.com/Hardening_WordPress
https://www.studiopress.com/tips/wordpress-site-security.htm

It is more likely some prior hacker left behind a back door script to re-hack your site (and less likely the version of WordPress has a relation to this issue).

So once you get things stable, start by resetting all your hosting and WordPress passwords.

A good start would be delete all inactive themes and plugins as well (to eliminate any potential entry points in those scripts).