We describe a novel method for malicious code obfuscationthat uses code already present in systems: a pseudo-randomnumber generator. This can also be seen as an anti-disassemblyand anti-debugging technique, depending on deployment, becausethe actual code does not exist until run - it is generateddynamically by the pseudo-random number generator.A year's worth of experiments are used to demonstrate thatthis technique is a viable code obfuscation option for amalicious adversary with access to large amounts of computingpower.