Detection rules › Sigma

Potential Browser Data Stealing

Status
test
Severity
medium
Log source
product windows, category process_creation
Author
Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

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.

MITRE ATT&CK coverage

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation

Rule body yaml

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

Stages and Predicates

Stage 0: condition

all of selection_*

Stage 1: selection_cmd

selection_cmd:
    - CommandLine|contains:
          - 'copy-item'
          - 'copy '
          - 'cpi '
          - ' cp '
          - 'move '
          - 'move-item'
          - ' mi '
          - ' mv '
    - Image|endswith:
          - '\esentutl.exe'
          - '\xcopy.exe'
          - '\robocopy.exe'
    - OriginalFileName:
          - 'esentutl.exe'
          - 'XCOPY.EXE'
          - 'robocopy.exe'

Stage 2: selection_path

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'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
CommandLinematch
  • cp corpus 8 (sigma 6, elastic 1, chronicle 1)
  • mi corpus 3 (sigma 2, chronicle 1)
  • mv corpus 4 (sigma 2, elastic 1, chronicle 1)
  • \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
  • \Vivaldi\User Data
  • \uCozMedia\Uran\User Data
  • copy corpus 12 (sigma 11, chronicle 1)
  • copy-item corpus 6 (sigma 5, chronicle 1)
  • cpi corpus 5 (sigma 4, chronicle 1)
  • move corpus 3 (sigma 2, chronicle 1)
  • move-item corpus 2 (sigma 1, chronicle 1)
Imageends_with
  • \esentutl.exe corpus 8 (sigma 8)
  • \robocopy.exe corpus 5 (sigma 5)
  • \xcopy.exe corpus 5 (sigma 5)
OriginalFileNameeq
  • XCOPY.EXE corpus 4 (sigma 4)
  • esentutl.exe corpus 4 (sigma 2, elastic 1, splunk 1)
  • robocopy.exe corpus 4 (sigma 4)