The invention relates to an apparatus for detecting malicious sites, comprising: a monitoring unit for monitoring all processes being executed in a computing apparatus; a hook code insertion unit for inserting a hook code in a process executed in a browser when the execution of the browser is detected by the monitoring unit; a danger level determining unit that, upon the detection of a website movement, uses the hook code to inspect a stack structure of a process implemented according to the website movement and determine whether or not to perform the stack structure inspection, and determines whether or not the website to which the movement has been made is a malicious site; and a database for storing a list of sites determined to be malicious.