Unusual Executable File Creation by a System Critical Processedit

Identifies an unexpected executable file being created or modified by a Windows system critical process, which may indicate activity related to remote code execution or other forms of exploitation.

Rule type: eql

Rule indices:

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

Severity: high

Risk score: 73

Runs every: 5 minutes

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

Maximum alerts per execution: 100

Tags:

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

Version: 4 (version history)

Added (Elastic Stack release): 7.10.0

Last modified (Elastic Stack release): 7.13.0

Rule authors: Elastic

Rule license: Elastic License v2

Rule queryedit

file where event.type != "deletion" and file.extension : ("exe",
"dll") and process.name : ("smss.exe",
"autochk.exe", "csrss.exe",
"wininit.exe", "services.exe",
"lsass.exe", "winlogon.exe",
"userinit.exe", "LogonUI.exe")

Threat mappingedit

Framework: MITRE ATT&CKTM

Rule version historyedit

Version 4 (7.13.0 release)
  • Updated query, changed from:

    event.category:file and not event.type:deletion and
    file.extension:(exe or dll) and process.name:(smss.exe or autochk.exe
    or csrss.exe or wininit.exe or services.exe or lsass.exe or
    winlogon.exe or userinit.exe or LogonUI.exe)
Version 3 (7.12.0 release)
  • Formatting only
Version 2 (7.11.2 release)
  • Formatting only