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Description

The following analytic detects when an email manually submitted to Microsoft through the Security & Compliance portal is found to be malicious. This capability is an enhanced protection feature that can be used within o365 tenants by administrative users to report potentially malicious emails. This correlation looks for any submission that returns a Phish or Malware verdict upon submission.

  • Type: TTP

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2024-04-01
  • Author: Steven Dick
  • ID: 94396c3e-7728-422a-9956-e4b77b53dbdf

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1566 Phishing Initial Access
T1566.001 Spearphishing Attachment Initial Access
T1566.002 Spearphishing Link Initial Access
Kill Chain Phase
  • Delivery
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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`o365_management_activity` Workload=SecurityComplianceCenter Operation=AdminSubmission 
| search RescanVerdict IN (Phish,Malware) 
| stats values(Subject) as subject, values(RescanVerdict) as result, values(SenderIP) as src, values(P2Sender) as sender, values(P1Sender) as src_user, values(Recipients{}) as user, count min(_time) as firstTime, max(_time) as lastTime, by Id,Operation,UserId 
| rename Name as signature, Id as signature_id, UserId as o365_adminuser 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `o365_email_reported_by_admin_found_malicious_filter`

Macros

The SPL above uses the following Macros:

:information_source: o365_email_reported_by_admin_found_malicious_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • Id
  • Operation
  • UserId

How To Implement

You must install splunk Microsoft Office 365 add-on. This search works with o365:management:activity

Known False Positives

Administrators that submit known phishing training exercises.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
50.0 50 100 O365 security admin $o365_adminuser$ manually reported a suspicious email from $src_user$

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

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

source | version: 1