Suspicious File Access to Browser Credential Storage — Sigma Rule

Rule metadata and linked tags

Author: frack113, X__Junior (Nextron Systems), Swachchhanda Shrawan Poudel (Nextron Systems), Parth-FourCore. Source status: experimental; severity: low. Source dates: 2025-05-22 / not supplied.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 497cdabe84fa601014ccb8ece37736862b4b3d0b9f4fcfb281c2e72f7f26751e

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: Suspicious File Access to Browser Credential Storage
id: a1dfd976-4852-41d4-9507-dc6590a3ccd0
status: experimental
description: |
    Detects file access to browser credential storage paths by non-browser processes, which may indicate credential access attempts.
    Adversaries may attempt to access browser credential storage to extract sensitive information such as usernames and passwords or cookies.
    This behavior is often commonly observed in credential stealing malware.
references:
    - https://github.com/splunk/security_content/blob/7283ba3723551f46b69dfeb23a63b358afb2cb0e/lookups/browser_app_list.csv?plain=1
    - https://fourcore.io/blogs/threat-hunting-browser-credential-stealing
author: frack113, X__Junior (Nextron Systems), Swachchhanda Shrawan Poudel (Nextron Systems), Parth-FourCore
date: 2025-05-22
tags:
    - attack.credential-access
    - attack.t1555.003
    - attack.discovery
    - attack.t1217
logsource:
    category: file_access
    product: windows
detection:
    selection_browser_paths:
        FileName|contains:
            - '\Sputnik\Sputnik'
            - '\MapleStudio\ChromePlus'
            - '\QIP Surf'
            - '\BlackHawk'
            - '\7Star\7Star'
            - '\CatalinaGroup\Citrio'
            - '\Google\Chrome'
            - '\Coowon\Coowon'
            - '\CocCoc\Browser'
            - '\uCozMedia\Uran'
            - '\Tencent\QQBrowser'
            - '\Orbitum'
            - '\Slimjet'
            - '\Iridium'
            - '\Vivaldi'
            - '\Chromium'
            - '\GhostBrowser'
            - '\CentBrowser'
            - '\Xvast'
            - '\Chedot'
            - '\SuperBird'
            - '\360Browser\Browser'
            - '\360Chrome\Chrome'
            - '\Comodo\Dragon'
            - '\BraveSoftware\Brave-Browser'
            - '\Torch'
            - '\UCBrowser\'
            - '\Blisk'
            - '\Epic Privacy Browser'
            - '\Nichrome'
            - '\Amigo'
            - '\Kometa'
            - '\Xpom'
            - '\Microsoft\Edge'
            - '\Liebao7Default\EncryptedStorage'
            - '\AVAST Software\Browser'
            - '\Kinza'
            - '\Mozilla\SeaMonkey\'
            - '\Comodo\IceDragon\'
            - '\8pecxstudios\Cyberfox\'
            - '\FlashPeak\SlimBrowser\'
            - '\Moonchild Productions\Pale Moon\'
    selection_browser_subpaths:
        FileName|contains:
            - '\Profiles\'
            - '\User Data'
    selection_cred_files:
        - FileName|contains:
              - '\Login Data'
              - '\Cookies'
              - '\EncryptedStorage'
              - '\WebCache\'
        - FileName|endswith:
              - 'cert9.db'
              - 'cookies.sqlite'
              - 'formhistory.sqlite'
              - 'key3.db'
              - 'key4.db'
              - 'Login Data.sqlite'
              - 'logins.json'
              - 'places.sqlite'
    filter_main_img:
        Image|endswith:
            - '\Sputnik.exe'
            - '\ChromePlus.exe'
            - '\QIP Surf.exe'
            - '\BlackHawk.exe'
            - '\7Star.exe'
            - '\Sleipnir5.exe'
            - '\Citrio.exe'
            - '\Chrome SxS.exe'
            - '\Chrome.exe'
            - '\Coowon.exe'
            - '\CocCocBrowser.exe'
            - '\Uran.exe'
            - '\QQBrowser.exe'
            - '\Orbitum.exe'
            - '\Slimjet.exe'
            - '\Iridium.exe'
            - '\Vivaldi.exe'
            - '\Chromium.exe'
            - '\GhostBrowser.exe'
            - '\CentBrowser.exe'
            - '\Xvast.exe'
            - '\Chedot.exe'
            - '\SuperBird.exe'
            - '\360Browser.exe'
            - '\360Chrome.exe'
            - '\dragon.exe'
            - '\brave.exe'
            - '\torch.exe'
            - '\UCBrowser.exe'
            - '\BliskBrowser.exe'
            - '\Epic Privacy Browser.exe'
            - '\nichrome.exe'
            - '\AmigoBrowser.exe'
            - '\KometaBrowser.exe'
            - '\XpomBrowser.exe'
            - '\msedge.exe'
            - '\LiebaoBrowser.exe'
            - '\AvastBrowser.exe'
            - '\Kinza.exe'
            - '\seamonkey.exe'
            - '\icedragon.exe'
            - '\cyberfox.exe'
            - '\SlimBrowser.exe'
            - '\palemoon.exe'
    filter_main_path:
        Image|contains:
            - '\Sputnik\'
            - '\MapleStudio\'
            - '\QIP Surf\'
            - '\BlackHawk\'
            - '\7Star\'
            - '\Fenrir Inc\'
            - '\CatalinaGroup\'
            - '\Google\'
            - '\Coowon\'
            - '\CocCoc\'
            - '\uCozMedia\'
            - '\Tencent\'
            - '\Orbitum\'
            - '\Slimjet\'
            - '\Iridium\'
            - '\Vivaldi\'
            - '\Chromium\'
            - '\GhostBrowser\'
            - '\CentBrowser\'
            - '\Xvast\'
            - '\Chedot\'
            - '\SuperBird\'
            - '\360Browser\'
            - '\360Chrome\'
            - '\Comodo\'
            - '\BraveSoftware\'
            - '\Torch\'
            - '\UCBrowser\'
            - '\Blisk\'
            - '\Epic Privacy Browser\'
            - '\Nichrome\'
            - '\Amigo\'
            - '\Kometa\'
            - '\Xpom\'
            - '\Microsoft\'
            - '\Liebao7\'
            - '\AVAST Software\'
            - '\Kinza\'
            - '\Mozilla\'
            - '\8pecxstudios\'
            - '\FlashPeak\'
            - '\Moonchild Productions\'
    filter_main_system:
        Image: System
        ParentImage: Idle
    filter_main_generic:
        Image|startswith:
            - 'C:\Program Files\'
            - 'C:\Program Files (x86)\'
            - 'C:\Windows\System32\'
            - 'C:\Windows\SysWOW64\'
    filter_optional_defender:
        Image|contains: '\Microsoft\Windows Defender\'
        Image|endswith:
            - '\MpCopyAccelerator.exe'
            - '\MsMpEng.exe'
    filter_optional_thor:
        Image|endswith:
            - '\thor.exe'
            - '\thor64.exe'
    filter_optional_msiexec:
        ParentImage: 'C:\Windows\System32\msiexec.exe'
    filter_optional_other:
        Image|endswith: '\everything.exe'
    condition: all of selection_* and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - Antivirus, Anti-Spyware, Anti-Malware Software
    - Legitimate software accessing browser data for synchronization or backup purposes.
    - Legitimate software installed on partitions other than "C:\"
level: low

Original YAML and metadata in JSON

False positives

• Antivirus, Anti-Spyware, Anti-Malware Software
• Legitimate software accessing browser data for synchronization or backup purposes.
• Legitimate software installed on partitions other than "C:\"

Source references

• https://github.com/splunk/security_content/blob/7283ba3723551f46b69dfeb23a63b358afb2cb0e/lookups/browser_app_list.csv?plain=1
• https://fourcore.io/blogs/threat-hunting-browser-credential-stealing