A method, system and computer-usable medium are disclosed for identifying security risks to a computer system based on a distribution of categorical features of events. Certain embodiments are directed to a computer-implemented method comprising: receiving a stream of events, the stream of events including a plurality of events; extracting a categorical feature from the plurality of events, where the categorical feature includes a set of categorical feature members, where the set of categorical feature members are generated on the fly from string values included in the extracted categorical feature; constructing a distribution for the categorical feature based on categorical feature members extracted from the plurality of events; and, analyzing the distribution of the categorical feature to identify one or more security risk factors.