A memory storage device, a memory controller, and a virus scanning method are provided. Each operating mode is controlled in the state where both positive-temperature-coefficient thermistors are thermally coupled to the temperature detection portion. For example, the surface-oxidized areas are one or more lowly-surface-oxidized areas and one or more highly-surface-oxidized areas. Areas of the secondary part are radially disposed inside and outside the discs which are made of a low-permeability magnetic material. The ligation cover covers at least a portion of the slot when in the closed, ligating position. The infrared transparent substrate has first and second major surfaces opposite each other, and the antireflection film is disposed on each of the first and second major surfaces of the substrate.