T1213.002 Google Chronicle · YARA-L

Detect Sharepoint in Google Chronicle

Adversaries may leverage SharePoint repositories as a source to mine valuable organizational information. SharePoint frequently contains policies, physical and logical network diagrams, system architecture documentation, testing credentials embedded in documents, source code snippets, and links to internal resources. Threat actors including Akira, HAFNIUM, LAPSUS$, APT28, and Chimera have used compromised credentials to bulk-access SharePoint sites during the collection phase, often prior to exfiltration. Specialized tooling such as spwebmember (used by APT15/Ke3chang) automates enumeration and bulk dumping of SharePoint document libraries.

MITRE ATT&CK

Tactic
Collection
Technique
T1213 Data from Information Repositories
Sub-technique
T1213.002 Sharepoint
Canonical reference
https://attack.mitre.org/techniques/T1213/002/

YARA-L Detection Query

Google Chronicle (YARA-L)
yaral
rule sharepoint_bulk_collection {
  meta:
    author = "Detection Engineering"
    description = "Detects bulk SharePoint data collection activity (T1213.002)"
    severity = "HIGH"
    tactic = "TA0009"

  events:
    $e.metadata.event_type = "USER_RESOURCE_ACCESS"
    $e.metadata.product_name = "Office 365"
    $e.target.application = "SharePoint"
    $e.metadata.product_event_type = /FileAccessed|FileDownloaded|SearchQueryPerformed/ nocase
    $user = $e.principal.user.userid
    $ip = $e.principal.ip

  match:
    $user, $ip over 1h

  outcome:
    $event_count = count_distinct($e.metadata.id)

  condition:
    $event_count > 30
}
high severity high confidence

YARA-L 2.0 rule detecting bulk SharePoint file access sessions in Chronicle UDM.

Data Sources

Microsoft 365 UDM Events

Required Tables

USER_RESOURCE_ACCESS

False Positives & Tuning

  • SharePoint site migrations or bulk content audits performed by IT administrators accessing large numbers of files in a short window
  • Automated backup or archiving tools (e.g., AvePoint, ShareGate, Veeam for Microsoft 365) that enumerate and download SharePoint content on a schedule
  • SharePoint crawlers and search indexers used by enterprise search products (Coveo, Microsoft Search, Elastic Workplace Search) that systematically access all content
  • Legal hold or eDiscovery processing tools (Purview, Nuix, Exterro) that access large document sets during compliance reviews
  • Power Automate flows or Logic Apps that process SharePoint file libraries at high volume for business automation workflows
Download portable Sigma rule (.yml)

Other platforms for T1213.002


Testing Methodology

Validate this detection against 4 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.

  1. Test 1SharePoint File Enumeration via PnP PowerShell

    Expected signal: OfficeActivity: Multiple FileAccessed and ListItemAccessed events within seconds, all from the same UserId and ClientIP. RecordType=SharePoint or SharePointListItemOperation. The rapid succession of events with consistent ClientIP and UserAgent ('NONISV|SharePoint|PnP.PowerShell') is the key signal. AADSignInLogs will show an interactive sign-in to SharePoint Online from the same IP.

  2. Test 2SharePoint REST API Bulk File Download

    Expected signal: OfficeActivity: FileAccessed events from the API enumeration, FileDownloaded events for each file retrieved. UserAgent will contain 'python-requests/<version>' — a non-browser UA string. ClientIP will be the test machine's IP. All events occur within seconds of each other, producing a high-rate signal. AADSignInLogs may show basic authentication (if enabled) or modern auth token acquisition.

  3. Test 3SharePoint Sensitive Document Search via Graph API

    Expected signal: OfficeActivity: SearchQueryPerformed events with QueryText fields containing the sensitive search terms. RecordType=SharePointSearch. ClientIP matches the test machine. UserAgent will reflect the requests library. AADSignInLogs shows app-only token acquisition from the Azure AD tenant. The hunting query 3 (sensitive search terms) will capture these events directly.

  4. Test 4SharePoint Cross-Site Collection Enumeration via PowerShell

    Expected signal: OfficeActivity: SiteCollectionAdminAdded or PageViewed events as the admin account traverses site collections. AADSignInLogs shows SharePoint Online Management Shell authentication (UserAgent: 'Microsoft SharePoint Online Management Shell'). The enumeration of site collection properties generates audit events in the SharePoint Admin Center audit log. The cross-site enumeration pattern (UniqueShareSites > 5) triggers the main detection query.

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