Sigma rule: Access To Browser Credential Files By Uncommon Applications - Security

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-1c0abd4d21ff, updated 2024-10-21T00:00:00.000Z.

Rule

Title
Access To Browser Credential Files By Uncommon Applications - Security
Status
test
Level
low
Author
Daniel Koifman (@Koifsec), Nasreddine Bencherchali
Date
2024-10-21
File
rules-threat-hunting/windows/builtin/security/win_security_file_access_browser_credential.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

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.

Log source

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_*

False positives (as the rule lists them)

  • Unknown

Tags

  • attack.credential-access
  • attack.t1555.003
  • detection.threat-hunting

MITRE ATT&CK ids this rule names

Related rules

References

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-threat-hunting/windows/builtin/security/win_security_file_access_browser_credential.yml

Sources and licences

  • SigmaHQ

    "Access To Browser Credential Files By Uncommon Applications - Security" by Daniel Koifman (@Koifsec), Nasreddine Bencherchali (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-threat-hunting/windows/builtin/security/win_security_file_access_browser_credential.yml.
    Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License

    Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: Access To Browser Credential Files By Uncommon Applications - Security",
entity page, dataset version ref-1c0abd4d21ff, updated 2024-10-21T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/4b60e527-ec73-4b47-8cb3-f02ad927ca65 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 4b60e527-ec73-4b47-8cb3-f02ad927ca65, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.