A real-time harmful website blocking method using an object attribute access engine is disclosed. In one embodiment, information about visual objects, currently being displayed on a screen by processes currently being executed, is obtained from a client. Attributes of the visual objects are extracted from the obtained information about the visual objects. Whether harmfulness is present is determined based on the extracted object attributes, and thus whether to block access to a server being connected thereto is decided. The client is requested to terminate a process for displaying the visual objects.