DETECTION DEVICE, DETECTION METHOD, AND DETECTION PROGRAM

1 . A detection device comprising:

a feature value database configured to store a packet feature value, a label assigned to each packet feature value, and a threshold used for determination in advance;

a memory; and

a processor coupled to the memory and configured to perform operations comprising:

converting a target packet into a feature value using a first natural language processing model that has been trained using normal communication packets as learning data;

assigning a label to the feature value converted using the first natural language processing model, based on the feature value converted using the first natural language processing model and the data stored in the feature value database; and

determining whether the target packet has an anomaly based on the assigned label.

2 . The detection device of claim 1 , wherein the operations further comprise:

outputting a notice related to the target packet to which the label is not assigned to the feature value; and

in a case where a label for the target packet is input, storing the feature value of the target packet and the input label in association with each other in the feature value database.

3 . The detection device claim 1 , wherein the operations further comprise:

in a case where it is input that the assigned label for the feature value is false, updating the threshold stored in the feature value database.

4 . The detection device of claim 1 , wherein the operations further comprise outputting a feature value to which a normal label is assigned among feature values converted using the first natural language processing model, as learning data of a first detection model for detecting intrusion.

5 . The detection device of claim 1 ,

wherein the feature value database is configured to store all or representative feature values used in pre-training in association with pre-training labels each indicating that it is a feature values used in the pre-training, and

wherein the operations further comprise determining whether a feature value is appropriately converted by the first natural language processing model, based on a similarity between the feature value to which the pre-training label is assigned and the feature value of the target packet, which has been converted using the first natural language processing model.

6 . The detection device of claim 5 , wherein the operations further comprise:

in a case where it is determined that that a feature value has been not appropriately converted by the first natural language processing model, establishing a new second natural language processing model, and;

training the second natural language processing model on conversion of the target packet into a feature value and;

outputting a feature value converted by the second natural language processing model, as learning data of a second detection model for detecting intrusion.

7 . The detection device of claim 6 , wherein the operations further comprise:

selecting a natural language processing model in which the converted feature value is most similar to the feature value of the packet that is learning data, among the first and second natural language processing models, and;

using the detection model corresponding to the selected natural language processing model to detect intrusion.

8 . A detection method performed by a computer, the detection method comprising:

converting a target packet into a feature value using a first natural language processing model that has been trained using normal communication packets as learning data;

assigning a label to the feature value converted using the first natural language processing model, based on the feature value converted using the first natural language processing model, a packet feature value obtained in advance, a label assigned to each packet feature value, and a threshold used in the determination, and;

determining whether the target packet has an anomaly based on the assigned label.

9 . A non-transitory computer readable storage medium having a detection program stored thereon that, when executed by a processor, causes the processor to perform operations comprising:

converting a target packet into a feature value using a first natural language processing model that has been trained using normal communication packets as learning data;

assigning a label to the feature value converted using the first natural language processing model, based on the feature value converted using the first natural language processing model, a packet feature value obtained in advance, a label assigned to each packet feature value, and a threshold used in the determination, and;

determining whether the target packet has an anomaly based on the assigned label.