Windows Event ID 4663: An attempt was made to access an object
- Applicable version
- Windows Server 2008 R2 and later; Windows 7 and later
- Last reviewed
- 2026-07-21
Quick summary
Event ID 4663 records access to an audited file, registry key, or other securable object.
Technical Metadata
| Event ID | 4663 |
|---|---|
| Provider | Microsoft-Windows-Security-Auditing |
| Channel | Security |
| Level | Information |
| Audit keyword | Audit Success |
| MITRE ATT&CK | TA0009 Collection / T1005 Data from Local System |
| Key fields to watch | Object Name, Access Mask, Process Name |
Trigger Scenarios
It fires only when the target has an SACL and the requested access matches the audit policy.
Key Fields
Object Name
The audited file or registry path.
Access Mask
0x2 is write data, 0x10000 is DELETE, and 0x40000 is WRITE_DAC; interpret it with Object Type.
Process Name
The process requesting access, essential for distinguishing users from tools.
Threat Hunting Queries
SecurityEvent
| where EventID == 4663
| project TimeGenerated, Computer, Account, EventData
| order by TimeGenerated desc- Data source
- Microsoft Sentinel SecurityEvent table
- Assumptions
- The Windows Security Events connector populates SecurityEvent. Apply the event-specific field and correlation guidance on this page after retrieving the base events.
index=wineventlog source="WinEventLog:Security" EventCode=4663
| table _time, host, user, EventCode, Message- Data source
- Splunk Windows Security event data
- Assumptions
- Index, source, and field aliases vary by Splunk deployment and Windows add-on version. Map provider fields from the raw event before adding event-specific filtering or aggregation.
dataset = microsoft_windows_raw
| filter edr_event_id = 4663- Data source
- Cortex XDR microsoft_windows_raw
- Assumptions
- The Windows Security channel is ingested into Cortex XDR. Inspect raw provider fields because parsed names vary by collection path.
title: Windows Security Event ID 4663
status: experimental
logsource:
product: windows
service: security
detection:
selection:
EventID: 4663
condition: selection
falsepositives:
- Legitimate administrative or system activity
level: informational- Data source
- Sigma Windows Security log source
- Assumptions
- This rule retrieves the event and is not a standalone malicious-behavior detection. Add the field conditions and correlations documented on this page in the destination SIEM.
Documented Values and Codes
| Field | Value | Meaning | Security relevance |
|---|---|---|---|
| AccessMask | 0x1 | For file objects, the requested access includes ReadData/ListDirectory. | Reading a sensitive local file supports collection triage when the process, account, and object are unexpected; the mask alone is common and benign in many workflows. Source |
| AccessMask | 0x2 | For file objects, the requested access includes WriteData/AddFile. | Unexpected writes to protected or monitored data can indicate staging, tampering, or ransomware and require object-specific context. Source |
| AccessMask | 0x10000 | DELETE access was requested for the object. | High-volume delete access against monitored files can support destructive-action or cleanup investigation when correlated with the responsible process. Source |
MITRE ATT&CK Mapping
- T1005Data from Local System
Detection Notes
Use 4663 for T1005 Data from Local System only when ObjectType and ObjectName identify sensitive local data and AccessMask includes 0x1 ReadData from an unexpected ProcessName. AccessMask 0x2 indicates writes and 0x10000 indicates delete access for file objects; retain ObjectType because the same bit can have different meanings for other object classes, then join ProcessId to 4688.
Common False Positives
- File servers and applications create substantial expected access noise.
- Backup and antivirus products request broad rights.
Related Events
Sample Log
Object Name: C:\Finance\payroll.xlsx
Access Mask: 0x1
Process Name: C:\Windows\System32\cmd.exeFrequently Asked Questions
What does Windows Event ID 4663 mean?
Event ID 4663 records that a process used an access right on an audited object, such as a file, registry key, kernel object, or Active Directory object.
Does AccessMask 0x1 always mean file read?
No. Access-mask meanings depend on ObjectType; for file objects 0x1 is ReadData/ListDirectory, so detection must retain the object type and requested-access text.
Why can Event ID 4663 be high volume?
Broad object SACLs can audit routine reads and writes; scope auditing to high-value objects and baseline approved processes and accounts.
Sources
- 4663: Microsoft Windows security auditing event reference
Microsoft · vendor
- Data from Local System (T1005)
MITRE ATT&CK · attack
- XDR Collector datasets
Palo Alto Networks · vendor
- Sigma Rules Specification
SigmaHQ · detection rule