It's been a couple of stressful hours here.

No we did not switch servers, we:
 - applied the Ruby Rails patch
 - backed up all log files for further analysis
 - log files show the XML code injection, we validated all triggered commands to ensure nothing other than withdrawing funds (e.g. backdoor) was done.
 
2AM here, will need to catch some sleep,  mistakes are easily made when being too tired.