Method and system for detecting fraudulent financial transaction

A fraudulent financial transaction detection method performed by a computer apparatus comprising processing circuitry, the fraudulent financial transaction detection method comprising:

• collecting, by the processing circuitry, transaction details from a financial institution;
• classifying, by the processing circuitry, each of a plurality of users into a respective set of groups among a plurality of groups for each of a plurality of transaction action types, the plurality of users corresponding to the transaction details;
• and
• determining, by the processing circuitry, whether a first user among the plurality of users is in a risk group based on a first set of groups among the plurality of groups into which the first user is classified.