Since the 1960s Supervisory Control and Data Acquisition (SCADA) systems have been used within industry. Referred to as critical infrastructure (CI), key installations such as power stations, water treatment and energy grids are controlled using SCADA. Existing literature reveals inherent security risks to CI and suggests this stems from the rise of interconnected networks, leading to the hypothesis that the rise of interconnectivity between corporate networks and SCADA system networks pose security risks to CI. The results from studies into previous global attacks involving SCADA and CI, with focus on two highly serious incidents in Iran and Ukraine, reveal that although interconnectivity is a major factor, isolated CIs are still highly vulnerable to attack due to risks within the SCADA controllers and protocols.