There are many definitions of the concept of event log files (log-file). In general, a log file means a file containing system information about the functioning of a particular site, server, and operating system. It is a computerized log file of records of events that have occurred over a period of time. Display of all actions initiated by the user in the operating system on the server or site is carried out in the logs. Generally, one record in the log file corresponds to one event. The record is made immediately after the start of the action and is supplemented after its completion. The given records are registered in the log either by the program, in which the user works, or they are sent by another special program, which main purpose is to compile information about the events that have occurred.