Modbus/TCP communication anomaly detection based on PSO-SVM

Industrial firewall and intrusion detection system based on Modbus TCP protocol analysis and "whitelist" policy cannot effectively identify attacks on Modbus controller which exactly take advantage of the configured rules. An Industrial control systems simulation environment is established and a data preprocessing method for Modbus TCP traffic captured is designed to meet the need of anomaly detection module. Furthermore a Modbus function code sequence anomaly detection model based on SVM optimized by PSO method is designed. And the model can effectively identify abnormal Modbus TCP traffic, according to frequency of different short mode sequences in a Modbus code sequence.