The invention generally provides an antivirus network system and method having a virtual scanning processor with plug-in functionalities. A preferred embodiment of the system according to the invention primarily comprises an antivirus scanning module operable with an operating system (OS), an antivirus database comprising a plurality of computer virus signatures, a library of external antivirus instructions wherein an antivirus system external to the network system is operable to update the external instructions, a virtual scanning processor further comprising a processor emulator operable to execute a plurality of internal antivirus instructions in detecting computer viruses based on the virus signatures, and a plug-in module connected to the processor emulator and the library and receiving the external instructions from the library, wherein the processor emulator is operable to execute the external instructions. The virtual scanning processor according to the invention is advantageously hardware-independent, i.e., is operable transparently to the hardware of a computer or network system. Moreover, the virtual scanning processor according to the invention is advantageously cross-platform, i.e., is operable transparently to, and regardless of the type of, the operating system (OS) it is operating in conjunction with.