The 'Box Untrusted Device Login' rule is designed to detect unauthorized login attempts to the Box application from devices not recognized as trusted. This rule is crucial for maintaining account integrity and security, as logging in from untrusted devices poses a potential risk of account compromise. When a user attempts to log into their Box account from a device that has not been previously authenticated or deemed secure, the rule logs this event. The severity of this threat is classified as 'Info', indicating that while it is noteworthy, it may not directly indicate an imminent threat. When triggered, it provides the relevant event details, including the type of event, user information, and device trust status, but it does not create an alert. The attached runbook advises performing an investigation to validate whether the login attempt is legitimate. Further context and actionable steps can be found in the referenced documentation on Box's device trust security requirements.