A method for blocking external debugger application from analysing code of software program installed on computing device. The method including initializing software program including an application program and an internal debugger application. The software program, upon initialization thereof, instructs internal debugger application to load application program in internal debugger application. The internal debugger application is configured to utilize kernel resources of an operating system of the computing device. The method includes executing internal debugger application to set one or more break-points in code of application program to define execution path for code of application program, executing application program as per defined execution path for code thereof, stopping execution of code of application program upon reaching any of one or more break-points therein, and handing control to internal debugger application to provide an address for next instruction to be executed in defined execution path for code of application program.