Detection rules › Sigma
Certutil root certificate installation
Detects scenarios where an attacker attempts to alter certificate chain validation by installing a root CA.
Known false positives
- Administrator manually adding a root CA
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Defense Impairment |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 1: Process creation |
| Security-Auditing | Event ID 4688: A new process has been created. |
Rule body
title: Certutil root certificate installation
description: Detects scenarios where an attacker attempts to alter certificate chain validation by installing a root CA.
references:
- https://twitter.com/Alh4zr3d/status/1592925753984880641
- https://specterops.io/wp-content/uploads/sites/3/2022/06/Certified_Pre-Owned.pdf
- https://posts.specterops.io/code-signing-certificate-cloning-attacks-and-defenses-6f98657fc6ec
- https://learn.microsoft.com/en-us/troubleshoot/windows-server/windows-security/import-third-party-ca-to-enterprise-ntauth-store#method-2---import-a-certificate-by-using-certutilexe
- https://strontic.github.io/xcyclopedia/library/certutil.exe-138DC8312317ED386C1CB62E19EA9269.html
tags:
- attack.defense_evasion
- attack.t1553.004 # Subvert Trust Controls: Install Root Certificate
author: mdecrevoisier
status: experimental
logsource:
product: windows
category: process_creation
detection: # certutil.exe -dspublish -f C:\rogue.crt NTAuthCA
selection:
NewProcessName|endswith: '\certutil.exe'
Commandline|contains|all:
- '-dspublish'
- '.crt'
- NTAuthCA
condition: selection
falsepositives:
- Administrator manually adding a root CA
level: high
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
selection:
NewProcessName|endswith: '\certutil.exe'
Commandline|contains|all:
- '-dspublish'
- '.crt'
- NTAuthCA
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
Commandline | match |
| field:"CommandLine" kind:match |
NewProcessName | ends_with |
| field:"Image" kind:ends_with value:"\certutil.exe" |