Create credential_access_mfa_push_brute_force.toml (#1682)

(cherry picked from commit 7e4325dd7a)

rules/integrations/okta/credential_access_mfa_push_brute_force.toml

@@ -0,0 +1,49 @@
+[metadata]
+creation_date = "2022/01/05"
+maturity = "production"
+updated_date = "2022/01/05"
+integration = "okta"
+
+[rule]
+author = ["Elastic"]
+description = """
+Detect when an attacker abuses the Multi-Factor authentication mechanism by repeatedly issuing login requests until the
+user eventually accepts the Okta push notification. An adversary may attempt to bypass the Okta MFA policies configured
+for an organization to obtain unauthorized access.
+"""
+index = ["filebeat-*", "logs-okta*"]
+language = "eql"
+license = "Elastic License v2"
+name = "Potential Abuse of Repeated MFA Push Notifications"
+note = """## Config
+
+The Okta Fleet integration, Filebeat module, or similarly structured data is required to be compatible with this rule."""
+references = ["https://www.mandiant.com/resources/russian-targeting-gov-business"]
+risk_score = 73
+rule_id = "97a8e584-fd3b-421f-9b9d-9c9d9e57e9d7"
+severity = "high"
+tags = ["Elastic", "Identity", "Okta", "Continuous Monitoring", "SecOps", "Identity and Access"]
+timestamp_override = "event.ingested"
+type = "eql"
+
+query = '''
+sequence by user.email with maxspan=10m
+  [any where event.module == "okta" and event.action == "user.mfa.okta_verify.deny_push"]
+  [any where event.module == "okta" and event.action == "user.mfa.okta_verify.deny_push"]
+  [any where event.module == "okta" and event.action == "user.authentication.sso"]
+'''
+
+
+[[rule.threat]]
+framework = "MITRE ATT&CK"
+
+[[rule.threat.technique]]
+id = "T1110"
+name = "Brute Force"
+reference = "https://attack.mitre.org/techniques/T1110/"
+
+[rule.threat.tactic]
+id = "TA0006"
+name = "Credential Access"
+reference = "https://attack.mitre.org/tactics/TA0006/"
+