name: Mailsniper Invoke functions
id: a36972c8-b894-11eb-9f78-acde48001122
version: 2
date: '2022-05-02'
author: Teoderick Contreras, Splunk
type: TTP
datamodel:
- Endpoint
description: This search is to detect known mailsniper.ps1 functions executed in a
  machine. This technique was seen in some attacker to harvest some sensitive e-mail
  in a compromised exchange server.
search: '`powershell` EventCode=4104 ScriptBlockText IN ("*Invoke-GlobalO365MailSearch*",
  "*Invoke-GlobalMailSearch*", "*Invoke-SelfSearch*", "*Invoke-PasswordSprayOWA*",
  "*Invoke-PasswordSprayEWS*","*Invoke-DomainHarvestOWA*", "*Invoke-UsernameHarvestOWA*","*Invoke-OpenInboxFinder*","*Invoke-InjectGEventAPI*","*Invoke-InjectGEvent*","*Invoke-SearchGmail*",
  "*Invoke-MonitorCredSniper*", "*Invoke-AddGmailRule*","*Invoke-PasswordSprayEAS*","*Invoke-UsernameHarvestEAS*")
  | stats count min(_time) as firstTime max(_time) as lastTime by Opcode Computer
  UserID EventCode ScriptBlockText | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`
  | `mailsniper_invoke_functions_filter`'
how_to_implement: To successfully implement this search, you need to be ingesting
  logs with the powershell logs  from your endpoints. make sure you enable needed
  registry to monitor this event.
known_false_positives: unknown
references:
- https://www.blackhillsinfosec.com/introducing-mailsniper-a-tool-for-searching-every-users-email-for-sensitive-data/
tags:
  analytic_story:
  - Data Exfiltration
  confidence: 80
  context:
  - Source:Endpoint
  - Stage:Exfiltration
  dataset:
  - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1059.001/powershell_script_block_logging/sbl_xml.log
  impact: 90
  kill_chain_phases:
  - Exploitation
  message: mailsniper.ps1 functions $ScriptBlockText$ executed on a $Computer$ by user
    $user$.
  mitre_attack_id:
  - T1114
  - T1114.001
  observable:
  - name: Computer
    type: Endpoint
    role:
    - Victim
  - name: user
    type: User
    role:
    - Victim
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - ScriptBlockText
  - Opcode
  - Computer
  - UserID
  - EventCode
  risk_score: 72
  security_domain: endpoint
  asset_type: Endpoint