Obfuscation: The Art of Creating Undetectable Malware

January 5, 2009 – 8:42 AM

Do not expect that your system would start misbehaving once it is infected by a malware. Malwares can perform their functions without showing any symptoms for days, months or years. New malwares are capable of hiding themselves even from powerful Antivirus scan engines. They can also perform their jobs without affecting the normal functionalities of the system.

Obfuscation helps malware writers to hide the malicious code on their programs. There are different types of obfuscation techniques like polymorphism, runtime packing, junk code injection etc. Obfuscation can also be as simple as code transposition or renaming the variable.

Obfuscation makes it time-consuming for an Antivirus program to analyze a malware program and when obfuscation is combined with encryption, it makes the malware more resistant to analysis. And it would be difficult for an Antivirus program to detect malicious code in an obfuscated program.

Source:
http://blog.isc2.org/isc2_blog/2009/01/obfuscation-the-art-of-creating-invisible-malware.html