Information Security Education Journal Arif SARI, Ersin CAGLAR 3 2 2016 Wireless Sensor Networks are prone to two major attacks, viz., the active and passive attacks and these attacks are aimed by five groups as classified in this paper. We in this study have described all the five attacks with a comprehensive architecture. We have detailed all possible defensive mechanisms against these five groups. Our descriptive enumeration as well as the reviews will enable the security systems to plan the defensive networks against all attacks.