Pin Configuration Attack
A PLC can receive and transmit various types of electrical and electronic signals. The input, which typically comes from sensors, and the output, which can be used to control motors, valves or relays, are linked to input and output pins on an integrated circuit known as a system on chip (SoC). The SoCís pin controller can configure the modes of a pin (i.e. they are set to serve as input or output). The experts discovered that an attacker who has compromised the PLC can tamper with the input and output without being detected and without alerting the operators monitoring the process through a human-machine interface (HMI).