Bom dia Ricardo A!
Tente isso
http://docs.joomla.org/Security_Checkli ... or_defaced
Depois poste o aconteceu
Abraço
Edilei
chmod and cron
IF you have permissions to access SSH (secure shell) via putty you can chmod the files and directories. If you do not have shell access, you can run the commands from cron by setting up a temporary cron job. Copy and paste the command into a cron job. Run the job about 2 minutes after saving the job. When using the command by putty or a cron job, the use of the full physical path to public_html is recommended for best results.
For files use:
find /home/xxxxxx/domains/xxxxxxx.com/public_html -type f -exec chmod 644 {} \;
and for directories use:
find /home/xxxxxx/domains/xxxxxxx.com/public_html -type d -exec chmod 755 {} \;