A client site was cleaned, and came back infected. Cleaned again, and came back again. Backdoors and rogue administrator accounts were part of it, but they were symptoms.
The cause was a 749MB full site backup sitting in a publicly reachable folder with the database credentials inside it. Anyone who found that file had everything, and no amount of malware removal was going to change that.
Care exists so that file is found during a routine month rather than during an incident.
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