Search results
Results From The WOW.Com Content Network
This differs from polymorphic code, where the polymorphic engine can not rewrite its own code. Metamorphic code is used by some viruses when they are about to infect new files, and the result is that the next generation will never look like current generation. The mutated code will do exactly the same thing (under the interpretation used), but
Polymorphic algorithms make it difficult for such software to recognize the offending code because it constantly mutates. Malicious programmers have sought to protect their encrypted code from this virus-scanning strategy by rewriting the unencrypted decryption engine (and the resulting encrypted payload) each time the virus or worm is propagated.
Oligomorphic code, also known as semi-polymorphic code, is a method used by a computer virus to obfuscate its decryptor by generating different versions of it, in order to evade detection by antivirus software. It is similar to, but less sophisticated than, polymorphic code. [1]
A polymorphic engine (sometimes called mutation engine or mutating engine) is a software component that uses polymorphic code to alter the payload while preserving the same functionality. Polymorphic engines are used almost exclusively in malware , with the purpose of being harder for antivirus software to detect.
Interest in polymorphic type systems developed significantly in the 1990s, with practical implementations beginning to appear by the end of the decade. Ad hoc polymorphism and parametric polymorphism were originally described in Christopher Strachey's Fundamental Concepts in Programming Languages, [5] where they are listed as "the two main classes" of polymorphism.
This metamorphic process is very complex and accounts for around 90% of the virus' code. After the rebuild, the virus searches for executable files in folders on all fixed and remote drives. Files will not be infected if they are located in a subfolder more than three levels deep, or if the folder name begins with the letter W.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
The use of templates as a metaprogramming technique requires two distinct operations: a template must be defined, and a defined template must be instantiated.The generic form of the generated source code is described in the template definition, and when the template is instantiated, the generic form in the template is used to generate a specific set of source code.