Overview

There are a series of extra filters, that perform analysis on credit card transactions to determine the likelihood that a transaction is fraudulent. Each of the filters helps determine the 'risk score' for a transaction. Actions to take based on certain risk scores can be configured per gateway (reject, review, challenge, accept). The filters currently available include:

MaxMind/MinFraud - a third party solution that helps analyze the transaction. They return their own 'risk score' for a transaction which heavily influences our own internal scoring.
Referrer - Regular expressions can be configured to be run on a transaction's 'referrer', and each regex can be configured to apply a different score in the event that the referrer is a match.
utm_source - Same as referrer, but for the utm_source bit in the tracking fields.