Transaction fraud detection based on entity linking

A computer-implemented method of establishing fraud links between transactions, comprising:

• collecting identifying data associated with at least one transaction in a set of fraudulent transactions;
• searching a second set of transactions for first linked transactions that include at least some of the identifying data;
• for each of the first linked transactions, recursively searching the second set of transactions for additional linked transactions based at least in part on additional identifying data included in each of the first linked transactions;
• designating a fraud island to include the at least one transaction, the first linked transactions, and the additional linked transactions;
• and
• determining whether at least one subsequent transaction is fraudulent based on the fraud island and a transaction fraud risk model.

A fraud detection system, comprising:

• a transaction processor configured to receive a first transaction;
• a transaction linker configured to determine a link between the first transaction and a fraud island, the fraud island comprising a plurality of linked transactions that includes at least one transaction identified as fraudulent, each transaction of the fraud island linked to at least one other transaction of the fraud island by a common at least one of an account identifier, a device fingerprint, an email address, or a payment instrument identifier;
• and
• a fraud detector configured to determine the first transaction as fraudulent based on the fraud island and a transaction fraud risk model.