Okta ThreatInsight Targeted Bruteforce Attack

/*
 * 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_threatinsight_targeted_brute_force_attack {

  meta:
    author = "Google Cloud Security"
    description = "Okta ThreatInsight detects access requests from known malicious IPs targeting a specific org."
    rule_id = "mr_ce576f12-ee6d-4282-9f7b-f955af183eb7"
    rule_name = "Okta ThreatInsight Targeted Bruteforce Attack"
    reference = "https://help.okta.com/en-us/Content/Topics/Security/threat-insight/configure-threatinsight-system-log.htm"
    mitre_attack_tactic = "Credential Access"
    mitre_attack_technique = "Brute Force"
    mitre_attack_url = "https://attack.mitre.org/techniques/T1110/"
    mitre_attack_version = "v13.1"
    type = "Alert"
    data_source = "Okta"
    severity = "Medium"
    priority = "Medium"

  events:
    $bruteforce.metadata.product_name = "Okta"
    $bruteforce.metadata.vendor_name = "Okta"
    $bruteforce.metadata.event_type = "USER_UNCATEGORIZED"
    $bruteforce.metadata.product_event_type = "security.attack.start"
    $bruteforce.principal.user.userid = $userid

  match:
    $userid over 1h

  outcome:
    $risk_score = max(35)
    $mitre_attack_tactic = "Credential Access"
    $mitre_attack_technique = "Brute Force"
    $principal_user_userid = array_distinct($bruteforce.principal.user.userid)
    $principal_user_email_addresses = array_distinct($bruteforce.principal.user.email_addresses)
    $security_result_summary = array_distinct($bruteforce.security_result.summary)
    $security_result_severity = array_distinct($bruteforce.security_result.severity)

  condition:
    $bruteforce
}