Slack User Privilege Escalation

AnalysisType: rule
Filename: slack_user_privilege_escalation.py
RuleID: "Slack.AuditLogs.UserPrivilegeEscalation"
DisplayName: "Slack User Privilege Escalation"
Enabled: true
LogTypes:
  - Slack.AuditLogs
Tags:
  - Slack
  - Privilege Escalation
  - Account Manipulation
  - Additional Cloud Roles
Reports:
  MITRE ATT&CK:
    - TA0004:T1098.003
Severity: High
Description: Detects when a Slack user gains escalated privileges
Reference: https://slack.com/intl/en-gb/help/articles/201314026-Permissions-by-role-in-Slack
DedupPeriodMinutes: 60
Threshold: 1
SummaryAttributes:
  - p_any_ip_addresses
  - p_any_emails
Tests:
  - Name: Owner Transferred
    ExpectedResult: true
    Log:
      {
        "action": "owner_transferred",
        "actor":
          {
            "type": "user",
            "user":
              {
                "email": "user@example.com",
                "id": "A012B3CDEFG",
                "name": "username",
                "team": "T01234N56GB",
              },
          },
        "context":
          {
            "ip_address": "1.2.3.4",
            "location":
              {
                "domain": "test-workspace",
                "id": "T01234N56GB",
                "name": "test-workspace",
                "type": "workspace",
              },
            "ua": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36",
          },
        "entity":
          {
            "type": "user",
            "user":
              {
                "email": "user@example.com",
                "id": "W012J3FEWAU",
                "name": "primary-owner",
                "team": "T01234N56GB",
              },
          },
      }
  - Name: Permissions Assigned
    ExpectedResult: true
    Log:
      {
        "action": "permissions_assigned",
        "actor":
          {
            "type": "user",
            "user":
              {
                "email": "user@example.com",
                "id": "A012B3CDEFG",
                "name": "username",
                "team": "T01234N56GB",
              },
          },
        "context":
          {
            "ip_address": "1.2.3.4",
            "location":
              {
                "domain": "test-workspace",
                "id": "T01234N56GB",
                "name": "test-workspace",
                "type": "workspace",
              },
            "ua": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36",
          },
        "entity":
          {
            "type": "user",
            "user":
              {
                "email": "user@example.com",
                "id": "W012J3FEWAU",
                "name": "primary-owner",
                "team": "T01234N56GB",
              },
          },
      }
  - Name: Role Changed to Admin
    ExpectedResult: true
    Log:
      {
        "action": "role_change_to_admin",
        "actor":
          {
            "type": "user",
            "user":
              {
                "email": "user@example.com",
                "id": "A012B3CDEFG",
                "name": "username",
                "team": "T01234N56GB",
              },
          },
        "context":
          {
            "ip_address": "1.2.3.4",
            "location":
              {
                "domain": "test-workspace",
                "id": "T01234N56GB",
                "name": "test-workspace",
                "type": "workspace",
              },
            "ua": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36",
          },
        "entity":
          {
            "type": "user",
            "user":
              {
                "email": "user@example.com",
                "id": "W012J3FEWAU",
                "name": "primary-owner",
                "team": "T01234N56GB",
              },
          },
      }
  - Name: Role Changed to Owner
    ExpectedResult: true
    Log:
      {
        "action": "role_change_to_owner",
        "actor":
          {
            "type": "user",
            "user":
              {
                "email": "user@example.com",
                "id": "A012B3CDEFG",
                "name": "username",
                "team": "T01234N56GB",
              },
          },
        "context":
          {
            "ip_address": "1.2.3.4",
            "location":
              {
                "domain": "test-workspace",
                "id": "T01234N56GB",
                "name": "test-workspace",
                "type": "workspace",
              },
            "ua": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36",
          },
        "entity":
          {
            "type": "user",
            "user":
              {
                "email": "user@example.com",
                "id": "W012J3FEWAU",
                "name": "primary-owner",
                "team": "T01234N56GB",
              },
          },
      }
  - Name: User Logout
    ExpectedResult: false
    Log:
      {
        "action": "user_logout",
        "actor":
          {
            "type": "user",
            "user":
              {
                "email": "user@example.com",
                "id": "W012J3FEWAU",
                "name": "primary-owner",
                "team": "T01234N56GB",
              },
          },
        "context":
          {
            "ip_address": "1.2.3.4",
            "location":
              {
                "domain": "test-workspace-1",
                "id": "T01234N56GB",
                "name": "test-workspace-1",
                "type": "workspace",
              },
            "ua": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/103.0.0.0 Safari/537.36",
          },
        "date_create": "2022-07-28 15:22:32",
        "entity":
          {
            "type": "user",
            "user":
              {
                "email": "user@example.com",
                "id": "W012J3FEWAU",
                "name": "primary-owner",
                "team": "T01234N56GB",
              },
          },
        "id": "72cac009-9eb3-4dde-bac6-ee49a32a1789",
      }


# ------ paired body: slack_user_privilege_escalation.py ------

from panther_slack_helpers import slack_alert_context

USER_PRIV_ESC_ACTIONS = {
    "owner_transferred": "Slack Owner Transferred",
    "permissions_assigned": "Slack User Assigned Permissions",
    "role_change_to_admin": "Slack User Made Admin",
    "role_change_to_owner": "Slack User Made Owner",
}


def rule(event):
    return event.get("action") in USER_PRIV_ESC_ACTIONS


def title(event):
    # This is the user taking the action.
    actor_username = event.deep_get("actor", "user", "name", default="<unknown-actor>")
    actor_email = event.deep_get("actor", "user", "email", default="<unknown-email>")
    # This is the user the action is taken on.
    entity_username = event.deep_get("entity", "user", "name", default="<unknown-actor>")
    entity_email = event.deep_get("entity", "user", "email", default="<unknown-email>")
    action = event.get("action")
    if action == "owner_transferred":
        return f"{USER_PRIV_ESC_ACTIONS[action]} from {actor_username} ({actor_email})"

    if action == "permissions_assigned":
        return f"{USER_PRIV_ESC_ACTIONS[action]} {actor_username} ({actor_email})"

    if action == "role_change_to_admin":
        return f"{USER_PRIV_ESC_ACTIONS[action]} {entity_username} ({entity_email})"

    if action == "role_change_to_owner":
        return f"{USER_PRIV_ESC_ACTIONS[action]} {entity_username} ({entity_email})"

    return f"Slack User Privilege Escalation event {action} on {entity_username} ({entity_email})"


def severity(event):
    # Downgrade severity for users assigned permissions
    if event.get("action") == "permissions_assigned":
        return "Medium"
    return "Critical"


def alert_context(event):
    return slack_alert_context(event)