Unusual File Creation - Alternate Data Stream

Elastic Stack Serverless Security

Identifies suspicious creation of Alternate Data Streams on highly targeted files. This is uncommon for legitimate files and sometimes done by adversaries to hide malware.

Rule type: eql

Rule indices:

winlogbeat-*
logs-endpoint.events.*
logs-windows.*

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: now-9m (https://www.elastic.co/guide/en/elasticsearch/reference/current/common-options.html#date-math[Date Math format], see also Additional look-back time)

Maximum alerts per execution: 100

References: None

Tags:

Elastic
Host
Windows
Threat Detection
Defense Evasion

Version: 4

Rule authors:

Elastic

Rule license: Elastic License v2

Investigation guide

Rule query

		file where event.type == "creation" and
  file.path : "C:\\*:*" and
  not file.path : "C:\\*:zone.identifier*" and
  file.extension :
    (
      "pdf",
      "dll",
      "png",
      "exe",
      "dat",
      "com",
      "bat",
      "cmd",
      "sys",
      "vbs",
      "ps1",
      "hta",
      "txt",
      "vbe",
      "js",
      "wsh",
      "docx",
      "doc",
      "xlsx",
      "xls",
      "pptx",
      "ppt",
      "rtf",
      "gif",
      "jpg",
      "png",
      "bmp",
      "img",
      "iso"
    )

	

Framework: MITRE ATT&CKTM

Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
Technique:
- Name: Hide Artifacts
- ID: T1564
- Reference URL: https://attack.mitre.org/techniques/T1564/
Sub-technique:
- Name: NTFS File Attributes
- ID: T1564.004
- Reference URL: https://attack.mitre.org/techniques/T1564/004/