Polymorphic Code

In computer technology, a polymorphic code if defined as an infection that mutates while maintaining it’s original encryption algorithm. This is a technique most commonly performed by viruses, shellcodes and worms in order to mask their presence. Many anti-virus programs and intrusion detection solutions attempt to find malicious codes by scanning files of the operating system and data packets transmitted over a network. If the software detects specific patterns that correspond to known infections, it takes the appropriate action in order to neutralize the problem. A polymorphic code makes it much harder for this type of code to be found as it is constantly mutating. Several methods of encryption are employed to achieve polymorphism within malicious code. Unlike algorithms applied in data security, not all codes from this type of infection can be decrypted. Small portions are not encrypted and used to initiate the encrypted files. For this reason, many security programs seek out that small portion during a scan.