name: Possible Browser Pass View Parameter
id: 8ba484e8-4b97-11ec-b19a-acde48001122
version: 1
date: '2021-11-22'
author: Teoderick Contreras, Splunk
type: Hunting
datamodel:
- Endpoint
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.
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
  as lastTime from datamodel=Endpoint.Processes where Processes.process  IN ("*/stext
  *", "*/shtml *", "*/LoadPasswordsIE*", "*/LoadPasswordsFirefox*", "*/LoadPasswordsChrome*",
  "*/LoadPasswordsOpera*", "*/LoadPasswordsSafari*" , "*/UseOperaPasswordFile*", "*/OperaPasswordFile*","*/stab*",
  "*/scomma*", "*/stabular*", "*/shtml*", "*/sverhtml*", "*/sxml*", "*/skeepass*"
  ) AND Processes.process IN ("*\\temp\\*", "*\\users\\public\\*", "*\\programdata\\*")
  by Processes.dest Processes.user Processes.parent_process_name Processes.parent_process
  Processes.process_name Processes.process Processes.process_id Processes.parent_process_id
  Processes.original_file_name | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)` | `possible_browser_pass_view_parameter_filter`'
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
  confidence: 40
  context:
  - Source:Endpoint
  - Stage:Credential Access
  dataset:
  - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1555/web_browser_pass_view/sysmon.log
  impact: 40
  kill_chain_phases:
  - Exploitation
  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
  required_fields:
  - _time
  - Processes.dest
  - Processes.user
  - Processes.parent_process_name
  - Processes.parent_process
  - Processes.original_file_name
  - Processes.process_name
  - Processes.process
  - Processes.process_id
  - Processes.parent_process_path
  - Processes.process_path
  - Processes.parent_process_id
  risk_score: 16
  security_domain: endpoint
  asset_type: Endpoint