Unusual Print Spooler Child Process

edit

Detects unusual Print Spooler service (spoolsv.exe) child processes. This may indicate an attempt to exploit privilege escalation vulnerabilities related to the Printing Service on Windows.

Rule type: eql

Rule indices:

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

Severity: medium

Risk score: 47

Runs every: 5m

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

Maximum alerts per execution: 100

References:

Tags:

  • Domain: Endpoint
  • OS: Windows
  • Use Case: Threat Detection
  • Tactic: Privilege Escalation
  • Use Case: Vulnerability
  • Data Source: Elastic Defend

Version: 106

Rule authors:

  • Elastic

Rule license: Elastic License v2

Rule query

edit
process where host.os.type == "windows" and event.type == "start" and
 process.parent.name : "spoolsv.exe" and process.command_line != null and
 (?process.Ext.token.integrity_level_name : "System" or ?winlog.event_data.IntegrityLevel : "System") and

 /* exclusions for FP control below */
 not process.name : ("splwow64.exe", "PDFCreator.exe", "acrodist.exe", "spoolsv.exe", "msiexec.exe", "route.exe", "WerFault.exe") and
 not process.command_line : "*\\WINDOWS\\system32\\spool\\DRIVERS*" and
 not (process.name : "net.exe" and process.command_line : ("*stop*", "*start*")) and
 not (process.name : ("cmd.exe", "powershell.exe") and process.command_line : ("*.spl*", "*\\program files*", "*route add*")) and
 not (process.name : "netsh.exe" and process.command_line : ("*add portopening*", "*rule name*")) and
 not (process.name : "regsvr32.exe" and process.command_line : "*PrintConfig.dll*") and
 not process.executable : (
    "?:\\Program Files (x86)\\CutePDF Writer\\CPWriter2.exe",
    "?:\\Program Files (x86)\\GPLGS\\gswin32c.exe"
 )

Framework: MITRE ATT&CKTM