This paper investigates the power sharing and voltage regulation issues of islanded single-/three-phase microgrids (S/T-MGs) where both sources and loads are unbalanced and the presence of adversarial cyber-attacks against sensors of distributed generator (DG) units is considered. Firstly, each DG unit is modeled as a heterogeneous linear dynamic agent with disturbances caused by sources and loads, then the problem is formulated as a distributed containment control problem. After that, to guarantee satisfactory power sharing and voltage control performance asymptotically achieved for the S/T-MGs, an attack-resilient distributed secondary control approach is developed by designing a distributed adaptive observer. With this approach, the effect of the cyber-attacks can be neutralized to ensure system stability and preserve bounded voltage synchronization. Simulation results are presented to demonstrate the effectiveness of the proposed control approach.