This paper defines and analyses a specific cybersecurity risk for EVs, which we refer to as Manipulation of Actual Demand. This attack involves coordinated charging of a large number of EVs across multiple charging stations to disrupt the power grid. We provide a detailed analysis and quantification of the impact of this unique cyber-attack on the smart grid in terms of demand-side load. The findings of our analysis guide future considerations on cybersecurity risks of coordinated EV charging and their mitigation. We have made a comparison between Home EV chargers and Fast EV chargers via simulation. The results indicate the EV demand load threshold required to disrupt normal power grid operations