Suspicious PrintSpooler Service Executable File Creation

Detects attempts to exploit privilege escalation vulnerabilities related to the Print Spooler service. For more information refer to the following CVE’s - CVE-2020-1048, CVE-2020-1337 and CVE-2020-1300 and verify that the impacted system is patched.

Rule type: eql

Rule indices:

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

Severity: high

Risk score: 73

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:

• https://voidsec.com/cve-2020-1337-printdemon-is-dead-long-live-printdemon/
• https://www.thezdi.com/blog/2020/7/8/cve-2020-1300-remote-code-execution-through-microsoft-windows-cab-files

Tags:

• Elastic
• Host
• Windows
• Threat Detection
• Privilege Escalation

Version: 101

Rule authors:

• Elastic

Rule license: Elastic License v2

file where event.type == "creation" and
  process.name : "spoolsv.exe" and file.extension : "dll" and
  file.path : ("?:\\Windows\\System32\\*", "?:\\Windows\\SysWOW64\\*") and
  not file.path :
          ("?:\\WINDOWS\\SysWOW64\\PrintConfig.dll",
           "?:\\WINDOWS\\system32\\x5lrs.dll",
           "?:\\WINDOWS\\sysWOW64\\x5lrs.dll",
           "?:\\WINDOWS\\system32\\PrintConfig.dll")

Framework: MITRE ATT&CKTM

• Tactic:

  • Name: Privilege Escalation
  • ID: TA0004
  • Reference URL: https://attack.mitre.org/tactics/TA0004/

• Technique:

  • Name: Exploitation for Privilege Escalation
  • ID: T1068
  • Reference URL: https://attack.mitre.org/techniques/T1068/