Implementing fraud controls on a hybrid network

A hybrid payment processing computer system operable to process both push transactions and pull transactions and to assess the probability of fraudulent activity during a payment transaction between a cardholder having a first account and a merchant having a merchant account comprising:

• a payment processor,
• a pull transaction database comprising details of past pull payment transactions,
• a push transaction database comprising details of past push payment transactions, wherein the push transaction database is separate from the pull transaction database;
• a fraud probability engine, and
• at least one communication node, the computer system configured to perform the steps of:
• receiving a request to process a push payment transaction from a first account at an issuing institution of a cardholder to a merchant account of a merchant at a separate, acquiring institution;
• determining that a first set of payment credentials is associated with the first account by identifying a correlation between credit account balance debts incurred in relation to the first set of payment credentials and settlement payments from the first account;
• determining that a second set of payment credentials are associated with the merchant account by:
• generating expected settlement amounts based on previous transaction authorizations made to the merchant with the second set of payment credentials, and
• identifying, based one or more settlement transactions from an acquirer account to the merchant account, a correlation between expected settlement amounts and the one or more settlement transactions;
• accessing the pull transaction database comprising pull payment transaction historical data indicating details of a plurality of past pull payment transactions between a plurality of cardholders and a plurality of merchants, and wherein a flag is associated with each fraudulent past pull payment transaction;
• accessing the push transaction database comprising push payment transaction historical data that is distinct from the pull payment transaction historical data, the push payment transaction historical data indicating details of past push payment transactions between the plurality of cardholders and their payment card providers;
• generating, by the payment processor using the fraud probability engine and based on the push payment transaction historical data, the pull payment transaction historical data and based on a transaction value, a fraud probability value for the push payment transaction from the first account to the merchant account, wherein the fraud probability value is an estimate of the probability of the push payment transaction being fraudulent;
• determining, based on the fraud probability value, that the push payment transaction has a high probability of being fraudulent;
• and
• declining the push payment transaction.