Suspicious PrintSpooler Service Executable File Creation

Elastic Stack Serverless Security

Detects attempts to exploit privilege escalation vulnerabilities related to the Print Spooler service. For more information refer to the following CVEs - 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: 5

Rule authors:

• Elastic

Rule license: Elastic License v2

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.

file where event.type != "deletion" and process.name : "spoolsv.exe" and
  file.extension : ("exe", "dll") and
  not file.path : ("?:\\Windows\\System32\\spool\\*", "?:\\Windows\\Temp\\*", "?:\\Users\\*")

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/