Profile cloning is a severe security issue in social networks since it is used to make a profile identical to existing ones. Profile cloning detection creates a possibility to detect frauds that would use people's trust to gather social information. This paper proposes two novel methods of profile cloning detection and also presents state-of-the-art research. The first method is based on the similarity of attributes from both profiles and the second method is based on the similarity of relationship networks. The methods are further evaluated with experiments and the results clearly describes that the proposed methods are useful and efficient compared to existing methods. The paper also stress that profile cloning in Facebook is not only possible but also fairly easy to perform.