okta_user_login_out_of_hours.yaral

/*
 * Copyright 2023 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

rule okta_user_login_out_of_hours {

  meta:
    author = "Google Cloud Security"
    description = "Detects out of hours successful authentication."
    reference = "https://support.okta.com/help/s/article/User-Signin-and-Recovery-Events-in-the-Okta-System-Log"
    mitre_attack_tactic = "Defense Evasion, Persistence, Privilege Escalation, Initial Access"
    mitre_attack_technique = "Valid Accounts"
    mitre_attack_url = "https://attack.mitre.org/techniques/T1078/"
    mitre_attack_version = "v13.1"
    type = "Alert"
    data_source = "Okta"
    severity = "Low"
    priority = "Low"

  events:
    $login.metadata.product_name = "Okta"
    $login.metadata.vendor_name = "Okta"
    $login.metadata.event_type = "USER_LOGIN"
    $login.target.user.email_addresses = $user
    $login.security_result.action = "ALLOW"
    $login.metadata.event_timestamp.seconds = $timestamp

    (
        01 = timestamp.get_day_of_week($timestamp, "UTC") or //Sunday
        07 = timestamp.get_day_of_week($timestamp, "UTC")  //Saturday
    )

  match:
    $user over 1h

  outcome:
    $risk_score = max(
        if (01 = timestamp.get_day_of_week($timestamp, "UTC"), 10) +
        if (07 = timestamp.get_day_of_week($timestamp, "UTC"), 15) +
        if ( ( timestamp.get_hour($timestamp, "UTC") >= 0 and timestamp.get_hour($timestamp,"UTC")<= 7) or timestamp.get_hour($timestamp,"UTC") > 20, 50)
    )
    $mitre_attack_tactic = "Defense Evasion, Persistence, Privilege Escalation, Initial Access"
    $mitre_attack_technique = "Valid Accounts"
    $principal_ip = array_distinct($login.principal.ip)
    $principal_ip_country = array_distinct($login.principal.ip_geo_artifact.location.country_or_region)
    $principal_ip_state = array_distinct($login.principal.ip_geo_artifact.location.state)
    $principal_ip_city = array_distinct($login.principal.location.city)
    $security_result_summary = array_distinct($login.security_result.summary)
    $principal_user_managers_email_addresses = array_distinct($login.principal.user.managers.email_addresses)
    $principal_user_userid = array_distinct($login.principal.user.userid)
    $dc_principal_user_userid = count_distinct($login.principal.user.userid)
    $target_user_email_addresses = array_distinct($login.target.user.email_addresses)
    $target_user_userid = array_distinct($login.target.user.userid)
    $target_user_agent = array_distinct($login.network.http.user_agent)
    $security_result_description = array_distinct($login.security_result.description)

  condition:
    $login
}