Suspicious Print Spooler File Deletion

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Detects deletion of print driver files by an unusual process. This may indicate a clean up attempt post successful privilege escalation via Print Spooler service related vulnerabilities.

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

References:

Tags:

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

Version: 2 (version history)

Added (Elastic Stack release): 7.14.0

Last modified (Elastic Stack release): 8.2.0

Rule authors: Elastic

Rule license: Elastic License v2

Potential false positives

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Uninstall or manual deletion of a legitimate printing driver files. Verify the printer file metadata such as manufacturer and signature information.

Investigation guide

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## 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 query

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file where event.type : "deletion" and not process.name :
("spoolsv.exe", "dllhost.exe", "explorer.exe") and file.path :
"?:\\Windows\\System32\\spool\\drivers\\x64\\3\\*.dll"

Threat mapping

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Framework: MITRE ATT&CKTM

Rule version history

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Version 2 (8.2.0 release)
  • Formatting only