Enabled Zendesk Support to Assume Users

AnalysisType: rule
Filename: zendesk_user_assumption.py
RuleID: "Zendesk.UserAssumption"
DisplayName: "Enabled Zendesk Support to Assume Users"
Enabled: true
LogTypes:
  - Zendesk.Audit
Tags:
  - Zendesk
  - Lateral Movement:Use Alternate Authentication Material
Reports:
  MITRE ATT&CK:
    - TA0008:T1550
Severity: Medium
Description: User enabled or disabled zendesk support user assumption.
Runbook: >
  Investigate whether allowing zendesk support to assume users is necessary. If not, disable the feature.
Reference: https://support.zendesk.com/hc/en-us/articles/4408894200474-Assuming-end-users#:~:text=In%20Support%2C%20click%20the%20Customers,user%20in%20the%20information%20dialog
SummaryAttributes:
  - p_any_ip_addresses
Tests:
  - Name: User assumption settings changed
    ExpectedResult: true
    Log:
      {
        "url": "https://myzendek.zendesk.com/api/v2/audit_logs/111222333444.json",
        "id": 123456789123,
        "action_label": "Updated",
        "actor_id": 123,
        "actor_name": "John Doe",
        "source_id": 123,
        "source_type": "account_setting",
        "source_label": "Account Assumption",
        "action": "update",
        "change_description": "Changed",
        "ip_address": "127.0.0.1",
        "created_at": "2021-05-28T18:39:50Z",
        "p_log_type": "Zendesk.Audit",
      }
  - Name: Zendesk - Credit Card Redaction On
    ExpectedResult: false
    Log:
      {
        "url": "https://myzendek.zendesk.com/api/v2/audit_logs/111222333444.json",
        "id": 123456789123,
        "action_label": "Updated",
        "actor_id": 123,
        "actor_name": "John Doe",
        "source_id": 123,
        "source_type": "account_setting",
        "source_label": "Credit Card Redaction",
        "action": "create",
        "change_description": "Enabled",
        "ip_address": "127.0.0.1",
        "created_at": "2021-05-28T18:39:50Z",
        "p_log_type": "Zendesk.Audit",
      }


# ------ paired body: zendesk_user_assumption.py ------

USER_SUSPENSION_ACTIONS = {
    "create",
    "update",
}


def rule(event):
    return (
        event.get("source_type") == "account_setting"
        and event.get("action", "") in USER_SUSPENSION_ACTIONS
        and event.get("source_label", "").lower() in {"account assumption", "assumption duration"}
    )


def title(event):
    return f"A user [{event.udm('actor_user')}] updated zendesk support user assumption settings"