Is it possible to have code rebuild itself

Question

I'm gonna use a program for an example, because the functions is what i'm trying to do. The program I will be using for example is JUST AN example and I am not trying to do anything that is related to what the said program does. Its just an example.

A lot of "hackers" use something called a "Crypter" to "Crypt" there program/file for "viruses" so Anti Viruses do not detect them. But after a while, the "Crypt" file is detectable and the "hacker" will have to rebuild the source code of the "Crypter" or the part that "Crypts" the file.

The "Crypter" is useally built in C, or .NET and maybe in other languages

Would it be possible to have the code of the"Crypter" to rebuild itself or the code that is used for the function? Instead of recoding it again?

I have a program that Crypts my programs. NOT what hackers do. But I always have to rebuild the source for AVS to not detect it. Its harmless but the code is always detected has a Trojan.

Answer 1

Yes, it is possible, and viruses already do it.

Answer 2

I think some virii have some code that looks at the assembly code of the application and rearranges/replaces instructions with others that do the same thing, or where ordering doesn't matter...to effectively make a totally different finger print for the application but without losing any functionality. This is a good but rather complicated solution