Malicious cyber-attacks are becoming increasingly prominent due to the advance of technology and attack methods over the last decade. These attacks have the potential to bring down critical infrastructures, such as nuclear power plants (NPP's), which are so vital to the country that their incapacitation would have debilitating effects on national security, public health, or safety. Despite the devastating effects a cyber-attack could have on NPP's, it is unclear how control room operations would be affected in such a situation. In this project, the authors are collaborating with NPP operators to discern the impact of cyber-attacks on control room operations and lay out a framework to better understand the control room operators' tasks and decision points. A cyber emulation of a digital control system was developed and coupled with a generic pressurized water reactor (GPWR) training simulator at Idaho National Laboratories. Licensed operators were asked to complete a series of scenarios on the simulator in which some of the scenarios were purposely obfuscated; that is, in which indicators were purposely displaying inaccurate information. Of interest is how this obfuscation impacts the ability to keep the plant safe and how it affects operators' perceptions of workload and performance. Results, conclusions and lessons learned from this pilot experiment will be discussed. This research sheds light onto about how cyber events impact plant operations.