Masquerade attacks based on user's profile

There are several problems related to security in computer networks. In this work only detection of masquerade attacks is explored. A masquerade attack occurs when an illegitimate user tries to impersonate a legitimate user; therefore, the masquerade user gets the privileges from the legitime user account. The task of detecting masquerade users is not easy since the masquerade user has yield the name and password of a valid user (probably an administrator). However, detecting illegitime users could be done if information about the behavior of the impersonate user is taken as a characteristic pattern which is valid only for this user.