Cloud Computing is an emerging area nowadays. Researchers are working on all aspects of cloud viz. cloud network architecture, scheduling policies, virtualization, hypervisor performance scalability, I/O efficiency, data integrity and data confidentiality of data intensive applications. The dynamic nature of cloud presents researchers new area of research that is cloud forensics. Cloud Forensics is the branch of forensics for applying computer science knowledge to prove digital artifacts. The DDOS is the widely used attack in cloud environment.