We recently inherited a Joomla! website from one of our client and the initial deal was to deploy, host and maintain it on our own servers. Upon inspecting their backup and noticing some PHP files over 200 Kb, it became quickly obvious that the website was infected by a malware.
Your clients complain that they cannot find your Joomla! website from Google, but you don't notice anything abnormal when visiting it? You are probably victim of an organic redirect hack, and this article may help you to solve the problem.