Malware are malicious software, capable of replicating themselves in network. They are designed to disrespect user choice of computing in network system. This paper presents current state of art of malware attacks and defense life cycle. We explored the characteristics of malware. We have presented the malware attack life-cycle. We have discussed different kind of strategies employed for target acquisition, transferring, and activation. Different kinds of malware employ different strategies in their attack life cycle. Therefore researchers have worked in different directions to cover the diversity of malware attacks. We have presented current state of art in malware defense. The purpose of this review is to point out the strength and challenges of contemporary malware defense mechanisms. We believe that this study will help security researchers in choosing appropriate mechanism for malware defense. The pros and cons of defense strategies will also helps in building more robust defense techniques in future.