Executable File Creation with Multiple Extensionsedit

Masquerading can allow an adversary to evade defenses and better blend in with the environment. One way it occurs is when the name or location of a file is manipulated as a means of tricking a user into executing what they think is a benign file type but is actually executable code.

Rule type: eql

Rule indices:

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

Severity: medium

Risk score: 47

Runs every: 5 minutes

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100


  • Elastic
  • Host
  • Windows
  • Threat Detection
  • Defense Evasion

Version: 4 (version history)

Added (Elastic Stack release): 7.12.0

Last modified (Elastic Stack release): 8.2.0

Rule authors: Elastic

Rule license: Elastic License v2

Investigation guideedit

## Config

If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2, events will not define `event.ingested` and default fallback for EQL rules was not added until 8.2, so you will need to add a custom pipeline to populate `event.ingested` to @timestamp for this rule to work.

Rule queryedit

file where event.type == "creation" and file.extension : "exe" and
file.name regex~ """.*\.(vbs|vbe|bat|js|cmd|wsh|ps1|pdf|docx?|xlsx?|pp

Threat mappingedit


Rule version historyedit

Version 4 (8.2.0 release)
  • Formatting only
Version 3 (7.16.0 release)
  • Formatting only
Version 2 (7.14.0 release)
  • Updated query, changed from:

    file where event.type == "creation" and file.extension:"exe" and
    file.name: ( "*.vbs.exe", "*.vbe.exe", "*.bat.exe",
    "*.js.exe", "*.cmd.exe", "*.wsh.exe", "*.ps1.exe",
    "*.pdf.exe", "*.docx.exe", "*.doc.exe", "*.xlsx.exe",
    "*.xls.exe", "*.pptx.exe", "*.ppt.exe", "*.txt.exe",
    "*.rtf.exe", "*.gif.exe", "*.jpg.exe", "*.png.exe",
    "*.bmp.exe", "*.hta.exe", "*.txt.exe", "*.img.exe",
    "*.iso.exe" )