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Description

The following analytic detects when any Microsoft Safe Links alerting is triggered. This behavior may indicate when user has interacted with a phishing or otherwise malicious link within the Microsoft Office ecosystem.

  • Type: TTP

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

  • Last Updated: 2024-03-30
  • Author: Steven Dick
  • ID: 711d9e8c-2cb0-45cf-8813-5f191ecb9b26

Annotations

ATT&CK

ATT&CK

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


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`o365_management_activity` Name="*a potentially malicious URL*" Operation=AlertEntityGenerated 
| fromjson Data 
| stats count min(_time) as firstTime max(_time) as lastTime values(ObjectId) as url values(od) as desc by AlertId,trc,Operation,Name,ot 
| rename Name as signature, AlertId as signature_id, trc as user,ot as action 
| eval action = CASE(action == "Allowed", "allowed", action=="BlockPageOverride", "allowed", true(),"blocked") 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `o365_safe_links_detection_filter`

Macros

The SPL above uses the following Macros:

:information_source: o365_safe_links_detection_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
  • AlertId
  • Operation
  • Name
  • AlertId
  • trc
  • ot

How To Implement

You must install the Splunk Microsoft Office 365 Add-on and ingest Office 365 management activity events. The Safe Links capability must be configured and is typically only available to E3/E5 level customers.

Known False Positives

Based on Safe Links policies, may vary.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
40.0 40 100 $user$ triggered a Microsoft Safe Links detection.

: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

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