For CC details to be stored the attacker needs to modify files though. Other payment gateways just process CC details locally, it is not stored. So either the a

For CC details to be stored the attacker needs to modify files though. Other payment gateways just process CC details locally, it is not stored. So either the attacker modifies files to store CC details - or the attacker gets access to log files (but CC details do not belong there either off course).