Potential Browser Data Stealing — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: medium. Source dates: 2022-12-23 / 2025-03-19.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 9810ad6f825c7e9a910db2246308049a9bc8c07d03982d765fcc34304f28081d

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: Potential Browser Data Stealing
id: 47147b5b-9e17-4d76-b8d2-7bac24c5ce1b
related:
    - id: fc028194-969d-4122-8abe-0470d5b8f12f
      type: derived
status: test
description: |
    Adversaries may acquire credentials from web browsers by reading files specific to the target browser.
    Web browsers commonly save credentials such as website usernames and passwords so that they do not need to be entered manually in the future.
    Web browsers typically store the credentials in an encrypted format within a credential store.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1555.003/T1555.003.md
    - https://www.cisa.gov/sites/default/files/2024-04/aa24-109a-stopransomware-akira-ransomware_2.pdf
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-12-23
modified: 2025-03-19
tags:
    - attack.credential-access
    - attack.t1555.003
logsource:
    category: process_creation
    product: windows
detection:
    selection_cmd:
        - CommandLine|contains:
              - 'copy-item'
              - 'copy '
              - 'cpi '
              - ' cp '
              - 'move '
              - 'move-item'
              - ' mi '
              - ' mv '
        - Image|endswith:
              - '\esentutl.exe' # akira ransomware
              - '\xcopy.exe'
              - '\robocopy.exe'
        - OriginalFileName:
              - 'esentutl.exe'
              - 'XCOPY.EXE'
              - 'robocopy.exe'
    selection_path:
        CommandLine|contains:
            - '\Amigo\User Data'
            - '\BraveSoftware\Brave-Browser\User Data'
            - '\CentBrowser\User Data'
            - '\Chromium\User Data'
            - '\CocCoc\Browser\User Data'
            - '\Comodo\Dragon\User Data'
            - '\Elements Browser\User Data'
            - '\Epic Privacy Browser\User Data'
            - '\Google\Chrome Beta\User Data'
            - '\Google\Chrome SxS\User Data'
            - '\Google\Chrome\User Data\'
            - '\Kometa\User Data'
            - '\Maxthon5\Users'
            - '\Microsoft\Edge\User Data'
            - '\Mozilla\Firefox\Profiles'
            - '\Nichrome\User Data'
            - '\Opera Software\Opera GX Stable\'
            - '\Opera Software\Opera Neon\User Data'
            - '\Opera Software\Opera Stable\'
            - '\Orbitum\User Data'
            - '\QIP Surf\User Data'
            - '\Sputnik\User Data'
            - '\Torch\User Data'
            - '\uCozMedia\Uran\User Data'
            - '\Vivaldi\User Data'
    condition: all of selection_*
falsepositives:
    - Unknown
level: medium

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1555.003/T1555.003.md
• https://www.cisa.gov/sites/default/files/2024-04/aa24-109a-stopransomware-akira-ransomware_2.pdf