A malicious code analysis device and method used on an external device connected via a USB cable. The malicious code analysis method includes connecting a malicious code analysis device to an analysis target terminal, on which malicious code is to be executed, from outside the analysis target terminal via a USB cable, multi-booting the analysis target terminal based on multiple Operating System (OS) image files stored in the malicious code analysis device; providing user input to the analysis target terminal so that malicious code is incapable of recognizing that a current environment is an analysis environment, and analyzing, by the malicious code analysis device, the malicious code in consideration of both data modified by the malicious code, among pieces of data corresponding to the multiple OS image files, and the user input.