Detection of alphanumeric shellcodes using similarity index

Shellcodes are widely used to exploit applications. Shellcodes can breach security and privacy to an unimaginable extent. Poor Programming results in various bugs that give attacker a chance to exploit an application. Exploiting an application allows attacker to inject a malicious code and transfer control of program to the injected code. The malicious code injected during exploitation is usually a shellcode. Detection of such shellcodes which are used for exploitation is an issue which concerns all the anti-virus companies. Attackers generally write shellcode in a way to bypass anti-virus engines. One such type of shellcodes is alphanumeric shellcodes. Despite of extensive advancement in detection technology detecting alphanumeric shellcodes still is not possible. This research paper presents a study of these kinds of alphanumeric shellcodes, effectiveness of current technology in detecting such shellcodes and also presents a novel approach to detect alphanumeric shellcodes.