Detection rules › Splunk

Windows Credentials from Web Browsers Saved in TEMP Folder

Status
production
Severity
medium
Group by
CreationUtcTime, computer_name, event_action, file_access_time, file_acl, file_hash, file_modify_time, file_name, file_size, process_guid, process_id, target_filename, user, vendor_product
Author
Teoderick Contreras, Splunk
Source
github.com/splunk/security_content

The following analytic detects the creation of files containing passwords, cookies, and saved login account information by the Braodo stealer malware in temporary folders. Braodo often collects these credentials from browsers and applications, storing them in temp directories before exfiltration. This detection focuses on monitoring for the creation of files with patterns or formats commonly associated with stolen credentials. By identifying these activities, security teams can take needed action to prevent sensitive login data from being leaked, reducing the risk of unauthorized access to user accounts and systems.

MITRE ATT&CK coverage

Event coverage

ProviderEventTitle
SysmonEvent ID 11FileCreate

Rule body splunk

name: Windows Credentials from Web Browsers Saved in TEMP Folder
id: b36b23ea-763c-417b-bd4a-6a378dabad1a
version: 10
creation_date: '2024-10-18'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: TTP
description: The following analytic detects the creation of files containing passwords, cookies, and saved login account information by the Braodo stealer malware in temporary folders. Braodo often collects these credentials from browsers and applications, storing them in temp directories before exfiltration. This detection focuses on monitoring for the creation of files with patterns or formats commonly associated with stolen credentials. By identifying these activities, security teams can take needed action to prevent sensitive login data from being leaked, reducing the risk of unauthorized access to user accounts and systems.
data_source:
    - Sysmon EventID 11
search: '|tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Filesystem where Filesystem.file_name IN ("login*", "pass*","cookie*","master_key*") Filesystem.file_path = "*\\temp\\*" by Filesystem.action Filesystem.dest Filesystem.file_access_time Filesystem.file_create_time Filesystem.file_hash Filesystem.file_modify_time Filesystem.file_name Filesystem.file_path Filesystem.file_acl Filesystem.file_size Filesystem.process_guid Filesystem.process_id Filesystem.user Filesystem.vendor_product | `drop_dm_object_name(Filesystem)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_credentials_from_web_browsers_saved_in_temp_folder_filter`'
how_to_implement: To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the `Endpoint` datamodel in the `Processes` node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product.
known_false_positives: No false positives have been identified at this time.
references:
    - https://x.com/suyog41/status/1825869470323056748
    - https://g0njxa.medium.com/from-vietnam-to-united-states-malware-fraud-and-dropshipping-98b7a7b2c36d
drilldown_searches:
    - name: View the detection results for "$dest$"
      search: '%original_detection_search% | search  dest = "$dest$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
finding:
    title: A known credential file name - [$file_name$] was saved in %temp% folder of [$dest$].
    entity:
        field: dest
        type: system
        score: 50
analytic_story:
    - Braodo Stealer
    - Scattered Lapsus$ Hunters
asset_type: Endpoint
mitre_attack_id:
    - T1555.003
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1555.003/browser_credential_info_temp/braodo_browser_info.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit

Stages and Predicates

Stage 1: tstats

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Filesystem where Filesystem.file_name IN ("login*", "pass*","cookie*","master_key*") Filesystem.file_path = "*\\temp\\*" by Filesystem.action Filesystem.dest Filesystem.file_access_time Filesystem.file_create_time Filesystem.file_hash Filesystem.file_modify_time Filesystem.file_name Filesystem.file_path Filesystem.file_acl Filesystem.file_size Filesystem.process_guid Filesystem.process_id Filesystem.user Filesystem.vendor_product

Stage 2: search

| `drop_dm_object_name(Filesystem)`

Stage 3: search

| `security_content_ctime(firstTime)`

Stage 4: search

| `security_content_ctime(lastTime)`

Stage 5: search

| `windows_credentials_from_web_browsers_saved_in_temp_folder_filter`

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
Filesystem.file_namein
  • "cookie*"
  • "login*"
  • "master_key*"
  • "pass*"
Filesystem.file_patheq
  • "*\\temp\\*" corpus 4 (splunk 4)