This is a spam bot attack . I had an an account at TNP HOST . When i contacted them they
1. Did a separate virus scan of my account using maldetect . This removed 50 % of malicious files .
2. Upgraded my wordpress to latest version .
3.Locked few database tables .
Also , after this they asked me to remove any malicious file and plugins that can cause the issue .
If in case the file reappears , please note that you have a plugin installed to recreate this file again and again .
Change the passwords of mysql database and reinsert the details in your wp-config files .
My problem is solved with TNP HOST . Hostgator people dont reply to such problem .. This is unfortunate
