[New Rule] Attempt to Modify an Okta Application (#495)

* Create okta_attempt_to_modify_okta_application.toml

* add reference

rules/okta/okta_attempt_to_modify_okta_application.toml

@@ -0,0 +1,37 @@
+[metadata]
+creation_date = "2020/11/06"
+ecs_version = ["1.6.0"]
+maturity = "production"
+updated_date = "2020/11/06"
+
+[rule]
+author = ["Elastic"]
+description = """
+Detects attempts to modify an Okta application. An adversary may attempt to modify, deactivate, or delete an Okta
+application in order to weaken an organization's security controls or disrupt their business operations.
+"""
+false_positives = [
+    """
+    Consider adding exceptions to this rule to filter false positives if your organization's Okta applications are
+    regularly modified and the behavior is expected.
+    """,
+]
+index = ["filebeat-*", "logs-okta*"]
+language = "kuery"
+license = "Elastic License"
+name = "Attempt to Modify an Okta Application"
+note = "The Okta Fleet integration or Filebeat module must be enabled to use this rule."
+references = [
+    "https://help.okta.com/en/prod/Content/Topics/Apps/Apps_Apps.htm",
+    "https://developer.okta.com/docs/reference/api/system-log/",
+    "https://developer.okta.com/docs/reference/api/event-types/",
+]
+risk_score = 21
+rule_id = "c74fd275-ab2c-4d49-8890-e2943fa65c09"
+severity = "low"
+tags = ["Elastic", "Identity", "Okta", "Continuous Monitoring", "SecOps", "Monitoring"]
+type = "query"
+
+query = '''
+event.dataset:okta.system and event.action:application.lifecycle.update
+'''