1. A computer-implemented method for identifying security risks, comprising: using at least one server connected to a computer network to perform the following actions: retrieving, via said computer network, a plurality of account credentials indications of a plurality of user accounts from a first group of machines in said computer network and generating a mapping dataset which maps said plurality of account credentials indications to machines in said first group, each of said plurality of account credentials indications is an indication of at least one of: a logon action made with authentication credentials of one of said plurality of user accounts on a member of said first group of machines, and a presence of said authentication credentials on a member of said first group of machines; collecting a plurality of account access rights, each one of said plurality of account access rights grants to one of said plurality of user accounts an access to at least one member of a second group of machines in said network; and identifying automatically at least one of a presence and absence of a plurality of security risks to at least one member of said second group by an analysis of said mapping database and a correlation between at least one of said plurality of account credentials indications and at least one of said plurality of account access rights; automatically generating a record of at least one of said presence and absence of said plurality of security risks; where said at least one account credentials indication and said at least one account access right is of the same account from said plurality of user accounts.