Fraud detection network system and fraud detection method

A fraud detection network system in which a web server device transmits a question that is randomly selected from combinations of a plurality of questions previously allocated for each user and correct answers therefor, in which the correct answer is returned from a user terminal device that is connected with a network such that authentication processing is performed, in which a service is thereafter provided and in which a fraud detection sever device connected to the network detects an unauthorized operation in the user terminal device,

• wherein the web server device includes:
• a storage means which stores web content information used for the provision of the service and a fraud detection script;
• and
• a content transmission means which transmits, after secure communication with the user terminal device is established, to the user terminal device, the web content information including the fraud detection script,
• the user terminal device includes:
• a content reception means which receives, after secure communication with the web server device is established, the web content information including the call script;
• a web browser processing means which displays the web content, which receives an information input from the user and which performs the fraud detection script;
• a fraud detection server communication means which communicates with the fraud detection server device,
• based on the fraud detection script, detection target data included in the web content information is searched, a result of the search is transmitted to the fraud detection server device and a predetermined fraud measure operation is performed based on a fraud detection result received from the fraud detection server device, and
• the fraud detection server device includes:
• a user terminal communication means which communicates with the user terminal device;
• and
• a fraud detection means which detects, on the result of the search by the fraud detection script, whether or not the unauthorized operation is present.

A fraud detection method in a fraud detection network system in which a web server device transmits a question that is randomly selected from combinations of a plurality of questions previously allocated for each user and correct answers therefor, in which the correct answer is returned from a user terminal device that is connected with a network such that authentication processing is performed, in which a service is thereafter provided and in which a fraud detection sever device connected to the network detects an unauthorized operation in the user terminal device, the fraud detection method comprising at least:

• a content transmission step of, by a content transmission means of the web server device, transmitting, after secure communication with the user terminal device is established, to the user terminal device, web content information used for the provision of the service including a call script for calling the fraud detection server device;
• a content reception step of, in the user terminal device, by a content reception means, after secure communication with the web server device is established, receiving the web content information including the call script;
• a fraud detection script acquisition step of, in the user terminal device, by a web browser processing means, acquiring a fraud detection script from the fraud detection server based on the call script;
• a search result transmission step of, in the user terminal device, searching detection target data included in the web content information based on the fraud detection script and transmitting a result of the search to the fraud detection server device;
• a fraud detection step of, in the fraud detection server device, by a fraud detection means, detecting on the result of the search whether or not the unauthorized operation is present and transmitting a fraud detection result to the user terminal device;
• and
• a fraud measure operation step of, in the fraud detection server device, by the web browser processing means of the user terminal device, performing a predetermined fraud measure operation based on the fraud detection result.

A fraud detection method in a fraud detection network system in which a web server device transmits a question that is randomly selected from combinations of a plurality of questions previously allocated for each user and correct answers therefor, in which the correct answer is returned from a user terminal device that is connected with a network such that authentication processing is performed, in which a service is thereafter provided and in which a fraud detection sever device connected to the network detects an unauthorized operation in the user terminal device, the fraud detection method comprising at least:

• a content transmission step of, after secure communication with the user terminal device is established, by a content transmission means of the web server device, transmitting, to the user terminal device, web content information used for the provision of the service including a fraud detection script;
• a content reception step of, in the user terminal device, after secure communication with the web server device is established, by a content reception means, receiving the web content information including the call script;
• a search result transmission step of, in the user terminal device, by a web browser processing means, searching detection target data included in the web content information based on the fraud detection script and transmitting a result of the search to the fraud detection server device;
• a fraud detection step of, in the fraud detection server device, by a fraud detection means, detecting on the result of the search whether or not the unauthorized operation is present and transmitting a fraud detection result to the user terminal device;
• and
• a fraud measure operation step of, in the fraud detection server device, by the web browser processing means of the user terminal device, performing a predetermined fraud measure operation based on the fraud detection result.