The Okta Impossible Travel Sign-In rule is designed to detect potentially malicious sign-in activity from a user who appears to log in from geographically disparate locations within an implausibly short time frame. This threat detection logic uses authentication data from Okta, specifically monitoring for user logins that occur in different cities or countries in quick succession. The detection mechanism leverages user geographic context and logs, analyzing the time distance between login attempts to identify anomalies. If the distance traveled between two login attempts surpasses a specific threshold, or the speed of travel calculated between two login locations exceeds realistic limits, the incident is flagged. This could indicate that a user's account has been compromised and may be under the control of a threat actor. The analysis employs various statistical functions to compute distances, compare login timestamps, and aggregate relevant information for alert generation. Such an approach helps identify compromised accounts associated with threat actor groups such as LUCR-3 and Scattered Spider, enhancing overall security posture against account takeover attempts.