Social networks are an indispensable attribute of Web 2.0 era. They are intended for communication of user groups, united by similar interests. Such networks can be dedicated to a single subject, as well as to many subjects, divided into different sections. Criminals are interested in users of social networks as a target for spam and in their computers as another link in a botnet. Today we will discuss the following points: 1. What is a social network? 2. Features of communication in social networks. 3. Contingent. 4. Aims of criminals. 5. Methods of Social Engineering: Links to sites, links to files. 6. XSS — Cross-Site Scripting Keywords: malware, trojan, botnet, malware propagation, social networks.