1. A computer system for an application group classification, the computer system comprising: one or more databases for including a plurality of application groups and a set of application classifying rules, wherein each application group has been classified based on the set of application classifying rules and includes one or more member applications sharing a set of common behavior patterns; and a computing device, in communication with the one or more databases, operative to: receive a request to classify an application into a corresponding application group among the plurality of application groups; obtain an event sequence which is collected while the application is being executed; determine the corresponding application group for the application by applying the set of application classifying rules to the obtained event sequence; and provide information about the determined application group as a response to the request.