Metamorphic Virus
Metamorphic viruses are programmed such that they rewrite themselves completely each time they infect a new executable file
- Such viruses are sophisticated and use metamorphic engines for their execution
- Metamorphic code reprograms itself
- It is translated into temporary code (a new variant of the same virus but with different code) and then converted back into the original code
- This technique, in which the original algorithm remains intact, is used to avoid pattern recognition by antivirus software
- Metamorphic viruses are more effective than polymorphic viruses
The transformation of virus bodies ranges from simple to complex, depending on the technique used. Some techniques used for metamorphosing viruses are as follows:
Virus bodies are transformed in the following steps:
- Inserts dead code
- Reshapes expressions
- Reorders instructions
- Modifies variable names
- Encrypts program code
- Modifies program control structure