Smart Grid is referred as next generation power system, and considered new revolutionary changes in existing traditional power system. Information Communication and Technologies (ICT) Integration in power grid enhance efficiency and reliability of future power systems. Power sector requires a secure distributed intelligence and customer demand based response along with an effective reusability of renewable energy resources. Despite, many silent features of Smart Grid, cyber attack risks are threatening the smart grid security. Malicious activities could be harm smart meters in distributed system and take out the power system in simulated attacks. Cyber attacks against Critical Infrastructures, like as Smart Grids, are especially dangerous, because they are tailored to disrupt assets, which are essential to the functioning of the society as whole. Critical Infrastructure sectors include Transportation, Communication and Technology utilities. Among these, the power system is possibly most critical, due to its strong dependency of all other Critical Infrastructures and involvement of Information Communication and Technology. In this paper, we illustrate introduction of smart grid, cyber attack. Current smart grid scenario in India and other countries in section I section II includes related work of cyber security and standard for smart grid while section III illustrated risk assessment, section IV elaborated proposed risk assessment framework and in last we conclude and describe further scope in this field paper in section V