Elastic Security Detection Rules

Suspicious File Renamed via SMB

Last updated a month ago on 2026-07-08
Created 2 years ago on 2024-05-02

About

Identifies suspicious file rename operation by the virtual System process. This may indicate a remote ransomware attack via the SMB protocol.
Tags
Domain: EndpointOS: WindowsUse Case: Threat DetectionTactic: ImpactData Source: Elastic DefendLanguage: eql
Severity
high
Risk Score
73
MITRE ATT&CK™

Impact (TA0040)(external, opens in a new tab or window)

↳ Data Destruction (T1485)(external, opens in a new tab or window)

↳ Data Encrypted for Impact (T1486)(external, opens in a new tab or window)

↳ Inhibit System Recovery (T1490)(external, opens in a new tab or window)

Lateral Movement (TA0008)(external, opens in a new tab or window)

↳ Remote Services (T1021)(external, opens in a new tab or window)

License
Elastic License v2(external, opens in a new tab or window)

Definition

Rule Type
Event Correlation Rule
Integration Pack
Prebuilt Security Detection Rules
Index Patterns
logs-endpoint.events.file-*
Related Integrations

endpoint(external, opens in a new tab or window)

Query
text code block:
sequence by host.id, file.extension with maxspan=1s
 [file where host.os.type == "windows" and
  event.action == "rename" and process.pid == 4 and user.id : ("S-1-5-21*", "S-1-12-*") and
  file.extension != null and file.Ext.entropy >= 6 and file.path : "C:\\Users\\*" and
  file.Ext.original.name : ("*.jpg", "*.bmp", "*.png", "*.pdf", "*.doc", "*.docx", "*.xls", "*.xlsx", "*.ppt", "*.pptx", "*.lnk") and
  not file.extension : ("jpg", "bmp", "png", "pdf", "doc", "docx", "xls", "xlsx", "ppt", "pptx", "lnk")] with runs=3

Install detection rules in Elastic Security

Detect Suspicious File Renamed via SMB in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(external, opens in a new tab or window).