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Description

This search is to detect suspicious google drive or google docs files shared outside or externally. This behavior might be a good hunting query to monitor exfitration of data made by an attacker or insider to a targetted machine.

  • Type: Anomaly
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud, Dev Sec Ops Analytics
  • Datamodel:
  • Last Updated: 2021-08-16
  • Author: Teoderick Contreras, Splunk
  • ID: f6ee02d6-fea0-11eb-b2c2-acde48001122

ATT&CK

ID Technique Tactic
T1567.002 Exfiltration to Cloud Storage Exfiltration
T1567 Exfiltration Over Web Service Exfiltration
`gsuite_drive` NOT (email IN("", "null")) 
| rex field=parameters.owner "[^@]+@(?<src_domain>[^@]+)" 
| rex field=email "[^@]+@(?<dest_domain>[^@]+)" 
| where src_domain = "internal_test_email.com" and not dest_domain = "internal_test_email.com" 
| eval phase="plan" 
| eval severity="low" 
| stats values(parameters.doc_title) as doc_title, values(parameters.doc_type) as doc_types, values(email) as dst_email_list, values(parameters.visibility) as visibility, values(parameters.doc_id) as doc_id, count min(_time) as firstTime max(_time) as lastTime by parameters.owner ip_address phase severity  
| rename parameters.owner as user ip_address as src_ip 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `gsuite_drive_share_in_external_email_filter`

Associated Analytic Story

How To Implement

To successfully implement this search, you need to be ingesting logs related to gsuite having the file attachment metadata like file type, file extension, source email, destination email, num of attachment and etc. In order for the search to work for your environment, please edit the query to use your company specific email domain instead of internal_test_email.com.

Required field

  • _time
  • parameters.doc_title
  • src_domain
  • dest_domain
  • email
  • parameters.visibility
  • parameters.owner
  • parameters.doc_type

Kill Chain Phase

  • Exfiltration

Known False Positives

network admin or normal user may share files to customer and external team.

RBA

Risk Score Impact Confidence Message
72.0 80 90 suspicious share gdrive from $parameters.owner$ to $email$ namely as $parameters.doc_title$

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

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