PURPOSE: A stack back-tracing apparatus is provided to block hacking by DLL injection or the modulated DLL by selectively performing malicious code inspection and to prevent unnecessary load. CONSTITUTION: A communication request monitoring unit(111) monitors a communication request of an application program. A thread reading unit(112) reads out an originating thread of the communication request. A module inspecting unit(113) traces a stack memory of the read thread. The module inspecting unit selectively monitors a module related to the communication request. A communication request processing unit(114) permits or blocks the communications request.
