For example, the simple math expressions 3+1 and 6-2 both achieve the same result, yet run with different machine code in a CPU.
If the security software finds patterns that correspond to known computer viruses or worms, it takes appropriate steps to neutralize the threat.
Polymorphic algorithms make it difficult for such software to recognize the offending code because it constantly mutates.
Emulation may be used to defeat polymorphic obfuscation by letting the malware demangle itself in a virtual environment before utilizing other methods, such as traditional signature scanning.
A better-known polymorphic virus was created in 1992 by the hacker Dark Avenger as a means of avoiding pattern recognition from antivirus software.