name: Possible Browser Pass View Parameter
id: 8ba484e8-4b97-11ec-b19a-acde48001122
version: 1
date: '2021-11-22'
author: Teoderick Contreras, Splunk
status: production
type: Hunting
description: This analytic will detect if a suspicious process contains a commandline
  parameter related to a web browser credential dumper. This technique is used by
  Remcos RAT malware which uses the Nirsoft webbrowserpassview.exe application to
  dump web browser credentials. Remcos uses the "/stext" command line to dump the
  credentials in text format. This Hunting query is a good indicator of hosts suffering
  from possible Remcos RAT infection. Since the hunting query is based on the parameter
  command and the possible path where it will save the text credential information,
  it may catch normal tools that are using the same command and behavior.
data_source:
- Sysmon Event ID 1
search:
  selection1:
    CommandLine:
    - '*\\temp\\*'
    - '*\\users\\public\\*'
    - '*\\programdata\\*'
  selection2:
    CommandLine:
    - '*/stext *'
    - '*/shtml *'
    - '*/LoadPasswordsIE*'
    - '*/LoadPasswordsFirefox*'
    - '*/LoadPasswordsChrome*'
    - '*/LoadPasswordsOpera*'
    - '*/LoadPasswordsSafari*'
    - '*/UseOperaPasswordFile*'
    - '*/OperaPasswordFile*'
    - '*/stab*'
    - '*/scomma*'
    - '*/stabular*'
    - '*/shtml*'
    - '*/sverhtml*'
    - '*/sxml*'
    - '*/skeepass*'
  condition: selection1 and selection2
how_to_implement: To successfully implement this search, you need to be ingesting
  logs with the process name, parent process, and command-line executions from your
  endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the
  Sysmon TA.
known_false_positives: False positive is quite limited. Filter is needed
references:
- https://www.nirsoft.net/utils/web_browser_password.html
- https://app.any.run/tasks/df0baf9f-8baf-4c32-a452-16562ecb19be/
tags:
  analytic_story:
  - Remcos
  asset_type: Endpoint
  confidence: 40
  impact: 40
  message: suspicious process $process_name$ contains commandline $process$ on $dest$
  mitre_attack_id:
  - T1555.003
  - T1555
  observable:
  - name: user
    type: User
    role:
    - Victim
  - name: dest
    type: Hostname
    role:
    - Victim
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  risk_score: 16
  security_domain: endpoint
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1555/web_browser_pass_view/sysmon.log
    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
    sourcetype: xmlwineventlog