Root Certificate Installed From Susp Locations — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: high. Source dates: 2022-09-09 / 2023-01-16.

{
  "category": "process_creation",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 39f604125a72aa5ed5a30c6b2f9d05c05e9255b2800d076a66800d23931b81d6

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Root Certificate Installed From Susp Locations
id: 5f6a601c-2ecb-498b-9c33-660362323afa
status: test
description: Adversaries may install a root certificate on a compromised system to avoid warnings when connecting to adversary controlled web servers.
references:
    - https://www.microsoft.com/security/blog/2022/09/07/profiling-dev-0270-phosphorus-ransomware-operations/
    - https://learn.microsoft.com/en-us/powershell/module/pki/import-certificate?view=windowsserver2022-ps
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-09-09
modified: 2023-01-16
tags:
    - attack.defense-impairment
    - attack.t1553.004
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        CommandLine|contains|all:
            - 'Import-Certificate'
            - ' -FilePath '
            - 'Cert:\LocalMachine\Root'
        CommandLine|contains:
            - '\AppData\Local\Temp\'
            - ':\Windows\TEMP\'
            - '\Desktop\'
            - '\Downloads\'
            - '\Perflogs\'
            - ':\Users\Public\'
    condition: selection
falsepositives:
    - Unlikely
level: high

Original YAML and metadata in JSON

False positives

• Unlikely

Source references

• https://www.microsoft.com/security/blog/2022/09/07/profiling-dev-0270-phosphorus-ransomware-operations/
• https://learn.microsoft.com/en-us/powershell/module/pki/import-certificate?view=windowsserver2022-ps