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.