First public release of GridAttackSim, the smart grid attack simulation framework that is being developed by the Cyber Range Organization and Design NEC-endowed chair at JAIST. GridAttackSim makes it possible to simulate various cyber-attacks on the smart grid infrastructure and visualize their consequences. The framework is extensible by end users, and the current release includes five smart grid topologies, two smart grid applications, and an attack library with four types of attacks.