Antivirus detections of PrinterNightmare PoC file creation path on Windows
Alerts on antivirus events where filenames include the Windows spooler driver x64 directory path, excluding Symantec submission messages.
- Category
- antivirus
- Author
- Sittikorn S, Nuttakorn T, Tim Shelton (SigmaHQ), DRL 1.1
- Published
- 2021-07-01
- Updated
- 2026-07-31
ATT&CK techniques
Priv Esc → Defense EvasionRecon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule identifies a suspicious file created with a Windows Print Spooler driver path commonly used in PrinterNightmare PoC activity. Attackers may drop or submit files into the spool driver directory to attempt exploitation, so matching this specific path helps surface potentially malicious PrinterNightmare-related behavior. It relies on antivirus telemetry that records the submitted filename and checks for a match on the expected System32 spool driver x64 location, while excluding a specific “File submitted to Symantec” message.
Reporting behind it
- twitter.comhttps://twitter.com/mvelazco/status/1410291741241102338
- msrc.microsoft.comhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-1675
- msrc.microsoft.comhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-34527
- github.comhttps://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2021/Exploits/CVE-2021-1675/av_exploit_cve_2021_34527_print_nightmare.yml
Changelog
v5- v5Candidate ingested via manual entry.2026-07-31
- v4Candidate ingested via manual entry.2026-07-31
- v3Candidate ingested via manual entry.2026-07-31
- v2Candidate ingested via manual entry.2026-07-31
- v1No changelog recorded for this version.2026-07-30
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
title: Antivirus detections of PrinterNightmare PoC file creation path on Windows
id: 63499f04-bb92-41d4-8a11-f6978a02d610
status: stable
description: |-
This rule identifies a suspicious file created with a Windows Print Spooler driver path commonly used in PrinterNightmare PoC activity. Attackers may drop or submit files into the spool
driver directory to attempt exploitation, so matching this specific path helps surface potentially malicious PrinterNightmare-related behavior. It relies on antivirus telemetry that records the submitted filename and checks for a match on the expected System32 spool driver x64 location, while excluding a specific “File submitted to Symantec” message.
references:
- https://twitter.com/mvelazco/status/1410291741241102338
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-1675
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-34527
- https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2021/Exploits/CVE-2021-1675/av_exploit_cve_2021_34527_print_nightmare.yml
author: Sittikorn S, Nuttakorn T, Tim Shelton, Huntrule Team
date: 2021-07-01
modified: 2023-10-23
tags:
- attack.privilege-escalation
- attack.stealth
- attack.t1055
- detection.emerging-threats
- cve.2021-34527
- cve.2021-1675
logsource:
category: antivirus
detection:
selection:
Filename|contains: :\Windows\System32\spool\drivers\x64\
keywords:
- File submitted to Symantec
condition: selection and not keywords
falsepositives:
- Unlikely, or pending PSP analysis
level: critical
license: DRL-1.1
related:
- id: 6fe1719e-ecdf-4caf-bffe-4f501cb0a561
type: derived