If you use any pre-packaged software, it always pays to sign up to their mailing list or security advisory list. This means if any exploits or updates happen, you are on the ball and up to date.
Today we had an email from a customer whos front page had been replaced. I noticed it was a drupal install, so i immediately checked http://drupal.org/security . Sure enough on the 16th of September there appears to be a new exploit out.
The good thing about using open source software is that its updated fast, I can now see the latest release was made a day after the bug was logged.
If you need to reinstall, then you can do this via the "Fresh Install" button on the Rimuhosting control panel . This takes an image of your VPS, then reinstalls it. You can then mount the old VPS image and copy over any files or configurations you need so you don't loose anything.
If for some reason your server was exploited, and you are unsure what to do, drop us an email at support and let us know.
See our howto for more information about avoiding, detecting and recovering from and exploit.