Detection rules › Splunk

Print Spooler Failed to Load a Plug-in

Author
Mauricio Velazco, Michael Haag, Splunk
Source
upstream

The following analytic detects driver load errors in the Windows PrintService Admin logs, specifically identifying issues related to CVE-2021-34527 (PrintNightmare). It triggers on error messages indicating the print spooler failed to load a plug-in module, such as "meterpreter.dll," with error code 0x45A. This detection method leverages specific event codes and error messages. This activity is significant as it may indicate an exploitation attempt of a known vulnerability. If confirmed malicious, an attacker could gain unauthorized code execution on the affected system, leading to potential system compromise.

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1547.012 Boot or Logon Autostart Execution: Print Processors
Privilege EscalationT1547.012 Boot or Logon Autostart Execution: Print Processors

Event coverage

ProviderEvent IDTitle
PrintService808The print spooler failed to load a plug-in module PluginDllName, error code ErrorCode.
PrintService4909Print Service event 4909 (manifest stub).

Stages and Predicates

Stage 1: search

search (EventCode="4909" OR EventCode="808") ErrorCode="0x45A"

Stage 2: stats

stats BY OpCode, EventCode, ComputerName, Message

Stage 3: search

search

Stage 4: search

search

Stage 5: search

search `macro`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
ErrorCodeeq
  • "0x45A"
EventCodeeq
  • "4909"
  • "808"