security-content/detections/account_harvesting.yml at develop · jwindley-splunk/security-content · GitHub

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asset_type: Account
confidence: medium
creation_date: '2018-07-12'
data_metadata:
  data_source:
    - Network Communications
  data_sourcetypes:
    - stream:http
  providing_technologies:
    - Splunk Stream
description: This search is used to identify the creation of multiple user accounts
  using the same email domain name.
detect:
  splunk:
    correlation_rule:
      notable:
        nes_fields: src_user
        rule_description: This search is used to identify multiple created accounts
          tied to a specific email domain. Such activity is often indicative of account
          harvesting. A list of $src_user$ accounts were created.
        rule_title: 'Web Fraud Detection: Possible Account Harvesting'
      risk:
        risk_object: src_user
        risk_object_type:
          - user
        risk_score: 40
      schedule:
        cron_schedule: 0 1 * * *
        earliest_time: -1445m@m
        latest_time: -10m@m
      search: sourcetype=stream:http http_content_type=text* uri="/magento2/customer/account/loginPost/"
        | rex field=cookie "form_key=(?<SessionID>\w+)" | rex field=form_data "login\[username\]=(?<Username>[^&|^$]+)"
        | search Username=* | rex field=Username "@(?<email_domain>.*)"|stats dc(Username)
        as UniqueUsernames list(Username) as src_user by email_domain|where UniqueUsernames>
        25
      suppress:
        suppress_fields: user
        suppress_period: 3600s
eli5: When a fraudster is setting the stage for a campaign, they will often create
  many user accounts on the website. This is a simple example of how to detect a many-account
  creation hosted on a Magento2 e-commerce platform, where the fraudster is using
  email addresses from a single email domain.
entities:
  - src_user
how_to_implement: We start with a dataset that provides visibility into the email
  address used for the account creation. In this example, we are narrowing our search
  down to the single web page that hosts the Magento2 e-commerce platform (via URI)
  used for account creation, the single http content-type to grab only the user's
  clicks, and the http field that provides the username (form_data), for performance
  reasons.  After we have the username and email domain, we look for numerous account
  creations per email domain.  Common data sources used for this detection are customized
  Apache logs or Splunk Stream.
id: 31337aaa-941d-4ada-81ac-q2a17be5bf0d
investigations:
  - id: 3d6c3213-5fff-4a1e-b57d-b24c262171e7
    name: Get Notable History
    type: splunk
  - id: f3fb4d1b-5f33-4b01-b541-c7af9534c242
    name: Get Notable Info
    type: splunk
  - id: bc91a8cf-35e7-4bb2-1120-e756cc06fd89
    name: Get Web Session Information via session_id
    type: splunk
  - id: 5df39b3f-447d-4869-b673-8f45ad4616fe
    name: Get Emails From Specific Sender
    type: splunk
known_false_positives: As is common with many fraud-related searches, we are usually
  looking to attribute risk or synthesize relevant context with loosely written detections
  that simply detect anamolous behavior. This search will need to be customized to
  fit your environment&#151;improving its fidelity by counting based on something
  much more specific, such as a device ID that may be present in your dataset. Consideration
  for whether the large number of registrations are occuring from a first-time seen
  domain may also be important.  Extending the search window to look further back
  in time, or even calculating the average per hour/day for each email domain to look
  for an anomalous spikes, will improve this search.  You can also use Shannon entropy
  or Levenshtein Distance (both courtesy of URL Toolbox) to consider the randomness
  or similarity of the email name or email domain, as the names are often machine-generated.
maintainers:
  - company: Splunk
    email: Mayhem@splunk.com
    name: Jim Apger
mappings:
  cis20:
    - CIS 16
  kill_chain_phases:
    - Actions on Objectives
  mitre_attack:
    - Persistence
    - Create Account
  nist:
    - DE.CM
    - DE.DP
modification_date: '2018-10-08'
name: Web Fraud - Account Harvesting
original_authors:
  - company: Splunk
    email: Mayhem@splunk.com
    name: Jim Apger
references:
  - https://splunkbase.splunk.com/app/2734/
  - https://splunkbase.splunk.com/app/1809/
security_domain: threat
spec_version: 2
type: splunk
version: '1.0'