{
  "id": "4733",
  "source": "windows_security",
  "priority": "P3",
  "applicable_version": "Windows Server 2008 and later where the audit subcategory is enabled",
  "last_reviewed": "2026-07-13",
  "category": "AccountManagement",
  "name": "A member was removed from a security-enabled local group",
  "definition": "Windows Security Event ID 4733 records removal of a member from a security-enabled local group.",
  "trigger_scenarios": "Microsoft documents that this event is generated for each removed member on domain controllers, member servers, and workstations.",
  "key_fields": [
    {
      "field": "Member Security ID / Account Name",
      "explanation": "The principal removed from the local security group; Account Name may be - for some local-group cases."
    },
    {
      "field": "Group Name / Group Domain",
      "explanation": "The local group affected; compare Group Domain to Computer to distinguish local SAM and domain local groups."
    },
    {
      "field": "Subject Logon ID / Privileges",
      "explanation": "Actor session and any privilege list associated with the removal."
    }
  ],
  "false_positives": [
    "Group Policy Preferences and endpoint management can enforce local Administrators membership and remove unmanaged principals.",
    "Deprovisioning and access review processes remove users from privileged local groups."
  ],
  "related_event_ids": [
    "4732",
    "4735",
    "4624"
  ],
  "attck_mapping": [
    {
      "technique_id": "T1098",
      "technique_name": "Account Manipulation"
    }
  ],
  "detection_notes": "Alert on threshold=1 removal from Administrators, Remote Desktop Users, Backup Operators, or other privileged local groups outside an approved endpoint-management cycle. Microsoft documents 4733 per removed member and notes 4735 often precedes it without details; a suspicious actor can remove competing administrators or cleanup evidence of earlier T1098 Account Manipulation. Correlate Subject Logon ID with 4624/4688 and compare Group Domain to Computer for local SAM scope.",
  "kql_snippet": "SecurityEvent\n| where EventID == 4733\n| project TimeGenerated, Computer, Account, MemberName, GroupName, GroupDomain",
  "spl_snippet": "index=wineventlog EventCode=4733 | table _time, host, Account_Name, Member_Account_Name, Group_Name, Group_Domain",
  "sample_log": "EventID: 4733\nSubject Account Name: admin.ops\nSubject Logon ID: 0x27a79\nMember Security ID: S-1-5-21-111-222-333-1109\nMember Account Name: CN=helpdesk,CN=Users,DC=corp,DC=local\nGroup Name: Administrators\nGroup Domain: HOST01",
  "source_url": "https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-10/security/threat-protection/auditing/event-4733",
  "route": "/windows-events/4733/",
  "canonical_url": "https://soceventlookup.com/windows-events/4733/",
  "json_url": "/api/events/windows-security/4733.json"
}