O365 ZAP Activity Detection

Description

The following analytic detects when the Microsoft Zero-hour Automatic Purge (ZAP) capability takes action against a user's mailbox. This capability is an enhanced protection feature that retro-actively removes email with known malicious content for user inboxes. Since this is a retroactive capability, there is still a window in which the user may fall victim to the malicious content.

Query · spl

`o365_management_activity` Workload=SecurityComplianceCenter Operation=AlertEntityGenerated Name="*messages containing malicious*"
  | fromjson Data
  | fillnull
  | stats count min(_time) as firstTime max(_time) as lastTime values(zu) as url values(zfn) as file_name values(ms) as subject values(ttr) as result values(tsd) as src_user
    BY AlertId,trc,signature,Name,dest,src,vendor_account,vendor_product
  | rename Name as signature, AlertId as signature_id, trc as user
  | eval action = CASE(match(result,"Success"), "blocked", true(),"allowed"), url = split(url,";")
  | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)`
  | `o365_zap_activity_detection_filter`

Implementation guide

You must install the Splunk Microsoft Office 365 Add-on and ingest Office 365 management activity events. Some features of Zero-hour purge are only offered within E3/E5 license level tenants, events may not be available otherwise.

Known false positives

  • No false positives have been identified at this time.

Analyst notes

Known false positives: No false positives have been identified at this time.

Raw source O365 ZAP Activity Detection · SPL
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Published by splunk/security_content ↗, licensed under Apache 2.0 ↗. Reproduced here unmodified. 
name: O365 ZAP Activity Detection
id: 4df275fd-a0e5-4246-8b92-d3201edaef7a
version: 12
creation_date: '2024-04-07'
modification_date: '2026-05-13'
author: Steven Dick
status: production
type: Anomaly
description: The following analytic detects when the Microsoft Zero-hour Automatic Purge (ZAP) capability takes action against a user's mailbox. This capability is an enhanced protection feature that retro-actively removes email with known malicious content for user inboxes. Since this is a retroactive capability, there is still a window in which the user may fall victim to the malicious content.
data_source:
    - Office 365 Universal Audit Log
search: |-
    `o365_management_activity` Workload=SecurityComplianceCenter Operation=AlertEntityGenerated Name="*messages containing malicious*"
      | fromjson Data
      | fillnull
      | stats count min(_time) as firstTime max(_time) as lastTime values(zu) as url values(zfn) as file_name values(ms) as subject values(ttr) as result values(tsd) as src_user
        BY AlertId,trc,signature,Name,dest,src,vendor_account,vendor_product
      | rename Name as signature, AlertId as signature_id, trc as user
      | eval action = CASE(match(result,"Success"), "blocked", true(),"allowed"), url = split(url,";")
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `o365_zap_activity_detection_filter`
how_to_implement: You must install the Splunk Microsoft Office 365 Add-on and ingest Office 365 management activity events. Some features of Zero-hour purge are only offered within E3/E5 license level tenants, events may not be available otherwise.
known_false_positives: No false positives have been identified at this time.
references:
    - https://learn.microsoft.com/en-us/microsoft-365/security/office-365-security/zero-hour-auto-purge?view=o365-worldwide
drilldown_searches:
    - name: View the detection results for - "$user$"
      search: '%original_detection_search% | search  user = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
intermediate_findings:
    entities:
        - field: user
          type: user
          score: 20
          message: User $user$ was included in a ZAP protection activity.
threat_objects:
    - field: file_name
      type: file_name
    - field: src_user
      type: email_address
    - field: url
      type: url
analytic_story:
    - Spearphishing Attachments
    - Suspicious Emails
asset_type: O365 Tenant
mitre_attack_id:
    - T1566.001
    - T1566.002
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: cloud
security_domain: threat
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1566/o365_various_alerts/o365_various_alerts.log
          sourcetype: o365:management:activity
          source: o365
      test_type: unit

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