The systems connected to the network are vulnerable to many malicious programs which threatens the confidentiality, integrity and availability of a system. Many malicious programs such as viruses, worms, Trojan horses, adware, scareware exists. A new malicious program has gained momentum known as spyware. Traditional techniques such as signature-based detection and heuristic-based detection have not performed well in detecting Spyware. Based on the recent studies it has been proven that data mining techniques yield better results than these traditional techniques.