Okta User Suspicious Activity Reported

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 * Copyright 2023 Google LLC
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 * 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
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 *     https://www.apache.org/licenses/LICENSE-2.0
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 * 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.
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rule okta_user_suspicious_activity_reported {

  meta:
    author = "Google Cloud Security"
    description = "An Okta user reports suspicious activity in response to an end user security notification."
    rule_id = "mr_09eaaa93-be5e-4b7f-9d6b-8675e63291a0"
    rule_name = "Okta User Suspicious Activity Reported"
    reference = "https://help.okta.com/en-us/Content/Topics/Security/suspicious-activity-reporting.htm"
    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 = "Medium"
    priority = "Medium"

  events:
    $suspicious.metadata.product_name = "Okta"
    $suspicious.metadata.vendor_name = "Okta"
    $suspicious.metadata.event_type = "USER_UNCATEGORIZED"
    $suspicious.metadata.product_event_type = "user.account.report_suspicious_activity_by_enduser"
    $suspicious.security_result.summary = "User report suspicious activity"
    $suspicious.target.user.userid = $userid

  match:
    $userid over 1h

  outcome:
    $risk_score = max(
      35 +
      // Increase Risk based on suspiciousActivityEventType
      if($suspicious.security_result.detection_fields["suspiciousActivityEventType"] = "system.email.mfa_enroll_notification.sent_message", 30)
    )
    $mitre_attack_tactic = "Defense Evasion, Persistence, Privilege Escalation, Initial Access"
    $mitre_attack_technique = "Valid Accounts"
    $target_user_agent = array_distinct($suspicious.network.http.user_agent)
    $principal_ip = array_distinct($suspicious.principal.ip)
    $principal_ip_country = array_distinct($suspicious.principal.ip_geo_artifact.location.country_or_region)
    $principal_ip_state = array_distinct($suspicious.principal.ip_geo_artifact.location.state)
    $principal_ip_city = array_distinct($suspicious.principal.location.city)
    $principal_user_email_addresses = array_distinct ($suspicious.principal.user.email_addresses)
    $security_result_summary = array_distinct($suspicious.security_result.summary)
    $target_user_email_addresses = array_distinct($suspicious.target.user.email_addresses)
    $target_user_userid = array_distinct($suspicious.target.user.userid)

  condition:
    $suspicious
}