Sysmon Event ID 15: FileCreateStreamHash
- Applicable version
- Sysmon with this event enabled
- Last reviewed
- 2026-07-22
Quick summary
Sysmon Event ID 15 records creation of a named file stream and hashes stream content.
Technical Metadata
| Event ID | 15 |
|---|---|
| Provider | Microsoft-Windows-Sysmon |
| Channel | Microsoft-Windows-Sysmon/Operational |
| Level | Informational |
| MITRE ATT&CK | TA0005 Defense Evasion / T1564.004 Hide Artifacts: NTFS File Attributes |
| Key fields to watch | TargetFilename, Hash / Contents, Image / ProcessGuid |
Trigger Scenarios
Microsoft documents that this event logs when a named file stream is created and records hashes of the unnamed file contents and the named stream, with Zone.Identifier as a common mark-of-the-web stream.
Key Fields
TargetFilename
The file and stream path. A colon suffix such as file.txt:payload.exe indicates an NTFS alternate data stream.
Hash / Contents
Sysmon records hashes of stream content, which should be used to preserve and triage the hidden payload.
Image / ProcessGuid
The process that created the stream and the join key to Event ID 1 command-line context.
Threat Hunting Queries
Event
| where EventLog == "Microsoft-Windows-Sysmon/Operational" and EventID == 15
| project TimeGenerated, Computer, EventID, RenderedDescription
| order by TimeGenerated desc- Data source
- Microsoft Sentinel Event table
- Assumptions
- The Sysmon Operational channel is collected into Event. Map raw XML fields to the event-specific fields described on this page.
index=sysmon source="WinEventLog:Microsoft-Windows-Sysmon/Operational" EventCode=15
| table _time, host, EventCode, Message- Data source
- Splunk Sysmon event data
- Assumptions
- Index, source, and parsed field names vary by deployment. Apply the documented field conditions after validating local field extraction.
dataset = microsoft_windows_raw
| filter edr_event_id = 15- Data source
- Cortex XDR microsoft_windows_raw
- Assumptions
- Confirm Provider is Microsoft-Windows-Sysmon because event IDs are not globally unique. Inspect raw provider fields because parsed names vary by collection path.
title: Sysmon Event ID 15
status: experimental
logsource:
product: windows
service: sysmon
detection:
selection:
EventID: 15
condition: selection
falsepositives:
- Legitimate administrative or system activity
level: informational- Data source
- Sigma Windows Sysmon log source
- Assumptions
- This rule retrieves the event and is not a standalone malicious-behavior detection. Add the event-specific conditions and correlations documented on this page.
Documented Values and Codes
| Field | Value | Meaning | Security relevance |
|---|---|---|---|
| EventID | 15 | A named file stream was created and its content was hashed. | Interpret EventID with the other documented fields and correlated events; this value alone is not proof of compromise. Source |
| TargetFilename | :Zone.Identifier | The browser Mark-of-the-Web alternate data stream documented by Sysinternals. | Interpret TargetFilename with the other documented fields and correlated events; this value alone is not proof of compromise. Source |
MITRE ATT&CK Mapping
- T1564.004Hide Artifacts: NTFS File Attributes
Detection Notes
Alert when TargetFilename contains an ADS suffix such as C:\Users\Public\invoice.txt:payload.exe or a non-Zone.Identifier stream under Downloads, Temp, or ProgramData. Microsoft documents Event 15 for named file streams and Zone.Identifier; MITRE T1564.004 covers Alternate Data Streams used to hide data. Correlate ProcessGuid to Event 1 and preserve the stream hash before deleting the host artifact.
Common False Positives
- Browsers create Zone.Identifier streams on downloaded files.
- Backup and endpoint tools may inspect or create metadata streams during scanning.
Related Events
Sample Log
UtcTime: 2026-07-13 03:03:00.000
Image: C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
TargetFilename: C:\Users\Public\invoice.txt:payload.exe
Hashes: SHA256=REDACTED
ProcessGuid: {REDACTED}Frequently Asked Questions
What does Sysmon Event ID 15 mean?
A named file stream was created and Sysmon recorded hashes and stream content.
Does Event ID 15 always indicate malicious activity?
No. Browsers routinely create Zone.Identifier streams on downloaded files.
How should Event ID 15 be investigated?
Distinguish Zone.Identifier from unusual stream names and correlate ProcessGuid with file creation and process execution.
Sources
- 15: FileCreateStreamHash
Microsoft Sysinternals · vendor
- Hide Artifacts: NTFS File Attributes (T1564.004)
MITRE ATT&CK · attack
- XDR Collector datasets
Palo Alto Networks · vendor
- Sigma Rules Specification
SigmaHQ · detection rule