1. An apparatus for use in processing an authentication request, the authentication request including a user identifier and current user data, the apparatus comprising: one or more processors; and a computer-readable medium storing instructions for execution by the one or more processors, the instructions comprising instructions to: receive the authentication request at an adaptive authentication system which includes a database having a set of entries, each entry of the set of entries including an identifier and previous user data in connection with previous authentication requests, the adaptive authentication system being constructed and arranged to perform an adaptive authentication operation on the authentication request, the adaptive authentication system being further constructed and arranged to perform an unsupervised machine learning operation on the authentication request; perform the adaptive authentication operation on the authentication request, including: matching the user identifier of the authentication request with an identifier of a particular entry of the database; performing an analysis between the current user data associated with the authentication request and previous user data of the particular entry; and generating an authentication result based on the analysis, the authentication result indicating a likelihood of the authentication request being associated with fraudulent activity; and perform the unsupervised machine learning operation on the authentication request, including: evaluating the current user data and previous user data of the particular entry; identifying a feature of user authentication behavior in response to the evaluation of the current user data and previous user data of the particular entry; and based on the identified feature, adjusting the adaptive authentication system to form an adjusted adaptive authentication system such that an adaptive authentication operation performed by the adjusted adaptive authentication system on an authentication request similar to the received authentication request will generate a different authentication result.