LoFP LoFP / false positives are unknown and filtering may be required.

Techniques

Sample rules

Description

The following analytic identifies driver load errors utilizing the Windows PrintService Admin logs. This was identified during our testing of CVE-2021-34527 previously (CVE-2021-1675) or PrintNightmare. Within the proof of concept code, the following error will occur - “The print spooler failed to load a plug-in module C:\Windows\system32\spool\DRIVERS\x64\3\meterpreter.dll, error code 0x45A. See the event user data for context information.” The analytic is based on file path and failure to load the plug-in. During triage, isolate the endpoint and review for source of exploitation. Capture any additional file modification events.

Detection logic

`printservice` ((ErrorCode="0x45A" (EventCode="808" OR EventCode="4909")) OR ("The print spooler failed to load a plug-in module" OR "\\drivers\\x64\\")) 
| stats count min(_time) as firstTime max(_time) as lastTime by OpCode EventCode ComputerName Message 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `print_spooler_failed_to_load_a_plug_in_filter`