Today I got that many of Joomla
websites on my server are hacked.
- Some of the hacked joomlas were updated (the last version from 2.5 series) with the last version.
- In many cases, the main index.php were hacked (not the index.php of their templates).
- Not ALL the joomla sites were hacked.
- The hosting control panel is Directadmin
- Centos's root password and Directadmin's admin password and the main reseller's password are strong enough.
- For each joomla, all user's passwords were changed.
- For one of the sites, the whole
images
folder were completely deleted.
The hacker might have let some backdoors for himself.
Previously this had happened, but since a very long time (about more than a year) this hadn't been occurred.
What should I do to make my server stronger enough? Is that very common?
I think that it's now the problem of the server, not the problem of each joomla site.