A malware detection method for a home network system including one or more home appliances that are connected to a home network includes: obtaining a plurality of setting values including at least information indicating a device type and an operating state of a target device subject to malware detection; selecting one detection model out of a plurality of detection models according to the plurality of setting values obtained; obtaining power consumption or current consumption of the target device; and detecting whether the target device is infected with malware, based on stable power or stable current obtained in the obtaining of the power consumption or the current consumption using the one detection model selected in the selecting, when the power consumption indicates stable power that varies within a predetermined range or the current consumption indicates stable current that varies within a predetermined range.