Windows Event ID 4733: A member was removed from a security-enabled local group
- Applicable version
- Windows Server 2008 and later where the audit subcategory is enabled
- Last reviewed
- 2026-07-22
Quick summary
Windows Security Event ID 4733 records removal of a member from a security-enabled local group.
Technical Metadata
| Event ID | 4733 |
|---|---|
| Provider | Microsoft-Windows-Security-Auditing |
| Channel | Security |
| Level | Information |
| MITRE ATT&CK | TA0040 Impact / T1531 Account Access Removal |
| Key fields to watch | Member Security ID / Account Name, Group Name / Group Domain, Subject Logon ID / Privileges |
Trigger Scenarios
Microsoft documents that this event is generated for each removed member on domain controllers, member servers, and workstations.
Key Fields
Member Security ID / Account Name
The principal removed from the local security group; Account Name may be - for some local-group cases.
Group Name / Group Domain
The local group affected; compare Group Domain to Computer to distinguish local SAM and domain local groups.
Subject Logon ID / Privileges
Actor session and any privilege list associated with the removal.
Threat Hunting Queries
SecurityEvent
| where EventID == 4733
| project TimeGenerated, Computer, EventID, RenderedDescription
| order by TimeGenerated desc- Data source
- Microsoft Sentinel SecurityEvent table
- Assumptions
- The Windows Security Events connector populates SecurityEvent. Map raw XML fields to the documented fields.
index=wineventlog source="WinEventLog:Security" EventCode=4733
| table _time, host, EventCode, Message- Data source
- Splunk Windows Security event data
- Assumptions
- Index and parsed field names vary by deployment. Add the documented event-specific conditions after field validation.
dataset = microsoft_windows_raw
| filter edr_event_id = 4733- Data source
- Cortex XDR microsoft_windows_raw
- Assumptions
- The Windows Security channel is ingested. Inspect raw fields because parsed names vary.
title: Windows Security Event ID 4733
status: experimental
logsource:
product: windows
service: security
detection:
selection:
EventID: 4733
condition: selection
falsepositives:
- Legitimate administrative or system activity
level: informational- Data source
- Sigma Windows Security log source
- Assumptions
- This retrieves the event and is not a standalone malicious-behavior detection.
Documented Values and Codes
| Field | Value | Meaning | Security relevance |
|---|---|---|---|
| MemberSid | SID | The principal removed from the local security group. | Interpret MemberSid with the full event and correlated activity; this value alone is not proof of compromise. Source |
| GroupName | Administrators | A privileged local group whose removals can revoke administrative access. | Interpret GroupName with the full event and correlated activity; this value alone is not proof of compromise. Source |
MITRE ATT&CK Mapping
- T1531Account Access Removal
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 T1531 Account Access Removal. Correlate Subject Logon ID with 4624/4688 and compare Group Domain to Computer for local SAM scope.
Common 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 Events
Sample Log
EventID: 4733
Subject Account Name: admin.ops
Subject Logon ID: 0x27a79
Member Security ID: S-1-5-21-111-222-333-1109
Member Account Name: CN=helpdesk,CN=Users,DC=corp,DC=local
Group Name: Administrators
Group Domain: HOST01Frequently Asked Questions
What does Windows Event ID 4733 mean?
A member was removed from a security-enabled local group.
Does Event ID 4733 always indicate malicious activity?
No. Endpoint management and access reviews routinely remove members.
How should Event ID 4733 be investigated?
Check whether the group is privileged, identify the subject and member, and correlate the subject logon to process creation.
Sources
- 4733: A member was removed from a security-enabled local group
Microsoft · vendor
- Account Access Removal (T1531)
MITRE ATT&CK · attack
- XDR Collector datasets
Palo Alto Networks · vendor
- Sigma Rules Specification
SigmaHQ · detection rule