Access To Browser Credential Files By Uncommon Applications - Security

Detects file access requests to browser credential stores by uncommon processes. Could indicate potential attempt of credential stealing This rule requires heavy baselining before usage.

title: Access To Browser Credential Files By Uncommon Applications - Security
id: 4b60e527-ec73-4b47-8cb3-f02ad927ca65
related:
    - id: 91cb43db-302a-47e3-b3c8-7ede481e27bf
      type: similar
status: test
description: |
    Detects file access requests to browser credential stores by uncommon processes. Could indicate potential attempt of credential stealing This rule requires heavy baselining before usage.
references:
    - https://ipurple.team/2024/09/10/browser-stored-credentials/
author: Daniel Koifman (@Koifsec), Nasreddine Bencherchali
date: 2024-10-21
tags:
    - attack.credential-access
    - attack.t1555.003
    - detection.threat-hunting
logsource:
    product: windows
    service: security
    definition: 'Requirements: Audit File System subcategory must be enabled. Additionally, each listed ObjectName must have "List folder/read data" auditing enabled.'
detection:
    selection_eid:
        EventID: 4663
        ObjectType: 'File'
        # Note: This AccessMask requires enhancements. As this access can be combined with other requests. It should include all possible outcomes where READ access and similar are part of it.
        AccessMask: '0x1'
    selection_browser_chromium:
        ObjectName|contains:
            - '\User Data\Default\Login Data'
            - '\User Data\Local State'
            - '\User Data\Default\Network\Cookies'
    selection_browser_firefox:
        FileName|endswith:
            - '\cookies.sqlite'
            - '\places.sqlite'
            - 'release\key3.db'  # Firefox
            - 'release\key4.db'  # Firefox
            - 'release\logins.json' # Firefox
    filter_main_system:
        ProcessName: System
    filter_main_generic:
        # This filter is added to avoid large amount of FP with 3rd party software. You should remove this in favour of specific filter per-application
        ProcessName|startswith:
            - 'C:\Program Files (x86)\'
            - 'C:\Program Files\'
            - 'C:\Windows\system32\'
            - 'C:\Windows\SysWOW64\'
    filter_optional_defender:
        ProcessName|startswith: 'C:\ProgramData\Microsoft\Windows Defender\'
        ProcessName|endswith:
            - '\MpCopyAccelerator.exe'
            - '\MsMpEng.exe'
    condition: selection_eid and 1 of selection_browser_* and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - Unknown
level: low

• T1555.003Credentials from Web Browsers

• https://ipurple.team/2024/09/10/browser-stored-credentials/↗