name: Previously Seen Users In CloudTrail - Update id: 66ff71c2-7e01-47dd-a041-906688c9d322 version: 1 date: '2020-05-28' author: Rico Valdez, Splunk type: Baseline datamodel: - Authentication description: This search looks for CloudTrail events where a user logs into the console, then updates the baseline of the latest and earliest times, City, Region, and Country we have encountered this user in our dataset, grouped by user, within the last hour. search: '| tstats earliest(_time) as firstTime latest(_time) as lastTime from datamodel=Authentication where Authentication.signature=ConsoleLogin by Authentication.user Authentication.src | iplocation Authentication.src | rename Authentication.user as user Authentication.src as src | table user src City Region Country firstTime lastTime | inputlookup append=t previously_seen_users_console_logins | stats min(firstTime) as firstTime max(lastTime) as lastTime by user src City Region Country | outputlookup previously_seen_users_console_logins' how_to_implement: You must install and configure the Splunk Add-on for AWS (version 5.1.0 or later) and Enterprise Security 6.2, which contains the required updates to the Authentication data model for cloud use cases. Validate the user name entries in `previously_seen_users_console_logins`, which is a lookup file created by this support search. known_false_positives: none references: [] tags: analytic_story: - Suspicious Cloud Authentication Activities deployments: - Daily Cache Updates detections: - Detect AWS Console Login by User from New Country - Detect AWS Console Login by User from New Region - Detect AWS Console Login by User from New City - Detect AWS Console Login by New User product: - Splunk Enterprise - Splunk Enterprise Security - Splunk Cloud required_fields: - _time - Authentication.signature - Authentication.user - Authentication.src security_domain: network