Many organizations have service accounts present on their network. A service account is a non-human account designated for performing a specific service-level function with appropriate privileges assigned to perform said function. Common Windows service accounts include LocalSystem and NetworkService. Linux service accounts include init and inetd. Cloud platforms also contain service accounts for high-level management of cloud services like Compute instances. Service accounts are important for network functionality, but they also pose a security risk if not secured and monitored properly. Documenting all service accounts is an essential first step to securing them. Privileged Account Management (PAM) solutions can assist in scanning your resources for current service accounts.
Many organizations also implement their own personalized service accounts that are shared amongst employees for performing various tasks. For example, you may create a basic non-human account for managing an Industrial Control System (ICS) which allows multiple employees on different shifts to run the system. A hardware store may have a basic account on a computer that controls the mixing settings for an attached paint mixer. The fact that these accounts are shared amongst multiple employees is a major security risk, as it reduces individual accountability. Make sure to document any shared accounts currently employed in your environment, along with the names of employees who have been granted access to them.