This paper proposes a smart inverter that is resilient against cyber-physical intrusion on the sensors. The proposed system is intended to detect intentional electromagnetic interference (EMI) injection in the current sensor data and to provide a healing solution for system restoration. A solution based on super-twisting sliding mode observer (STSMO) is designed to estimate the grid current. The proposed solution is aimed to detect the jeopardized current sensor due to the cyber-physical attack by taking into consideration the error between the observed and measured currents. In addition, this work adopts the flatness-based control (FBC) technique to control the inverter and feed the current to the grid with low harmonic content even under EMI attack. The adopted flatness controller relies on the reference feedback instead of disturbance feedback which helps in reducing the external noises. Therefore, the proposed solution is suitable to establish a safe and secure connection of the inverters to the grid. Real-time simulation results are carried out to prove the concept of the proposed solution.