Credential Manager Access By Uncommon Applications — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: medium. Source dates: 2022-10-11 / 2024-07-29.

{
  "category": "file_access",
  "product": "windows",
  "definition": "Requirements: Microsoft-Windows-Kernel-File ETW provider"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 52ca57ffea329745c5bebcb6f41c57f4b15ea27faa98789f5691503a3ee4b06e

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: Credential Manager Access By Uncommon Applications
id: 407aecb1-e762-4acf-8c7b-d087bcff3bb6
status: test
description: |
    Detects suspicious processes based on name and location that access the windows credential manager and vault.
    Which can be a sign of credential stealing. Example case would be usage of mimikatz "dpapi::cred" function
references:
    - https://hunter2.gitbook.io/darthsidious/privilege-escalation/mimikatz
    - https://www.absolomb.com/2018-01-26-Windows-Privilege-Escalation-Guide/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-10-11
modified: 2024-07-29
tags:
    - attack.t1003
    - attack.credential-access
logsource:
    category: file_access
    product: windows
    definition: 'Requirements: Microsoft-Windows-Kernel-File ETW provider'
detection:
    selection:
        FileName|contains:
            - '\AppData\Local\Microsoft\Credentials\'
            - '\AppData\Roaming\Microsoft\Credentials\'
            - '\AppData\Local\Microsoft\Vault\'
            - '\ProgramData\Microsoft\Vault\'
    filter_system_folders:
        Image|startswith:
            - 'C:\Program Files\'
            - 'C:\Program Files (x86)\'
            - 'C:\Windows\system32\'
            - 'C:\Windows\SysWOW64\'
    condition: selection and not 1 of filter_*
falsepositives:
    - Legitimate software installed by the users for example in the "AppData" directory may access these files (for any reason).
# Increase level after false positives filters are good enough
level: medium

Original YAML and metadata in JSON

False positives

• Legitimate software installed by the users for example in the "AppData" directory may access these files (for any reason).

Source references

• https://hunter2.gitbook.io/darthsidious/privilege-escalation/mimikatz
• https://www.absolomb.com/2018-01-26-Windows-Privilege-Escalation-Guide/