The Detecting Abnormal Operations in ICS Using Finite-State Machines

In 2021, a water treatment facility in Florida, USA, fell victim to an external malicious attack.inthis incident, malicious actors attempted to manipulate the quantities of specific chemicals to impact water quality and safety.Given the intricacies of abnormal operation detection in Industrial Control Systems and the advantages of finite-state machine, we endeavored to apply this approach for the detection of abnormal ICS (Industrial Control System) operations.We conducted a series of tests using the dam control system cybersecurity testbed established by TWISC@NCKU, Taiwan.The results indicate that our approach effectively enhances the efficiency of identifying non-standard operational behaviors, enabling maintenance personnel to promptly identify anomalies.