Microsoft 365 traffic is actively flowing through Global Secure Access

Overview

When Microsoft 365 traffic bypasses Global Secure Access, organizations lose visibility and control over their most critical productivity workloads. Threat actors who exploit unmonitored Microsoft 365 connections can exfiltrate sensitive data through SharePoint, OneDrive, or Exchange without triggering security policies or generating actionable telemetry. Token theft and replay attacks become more difficult to detect when traffic doesn’t flow through the Security Service Edge because source IP correlation with sign-in logs and Conditional Access evaluation can’t be applied consistently.

Organizations with significant bypassed traffic, whether due to incomplete client deployment, misconfigured forwarding profiles, or users on unmanaged devices, create blind spots where adversary-in-the-middle attacks, credential harvesting, and unauthorized data transfers can proceed undetected. Traffic that bypasses Global Secure Access also can’t benefit from compliant network checks in Conditional Access policies, tenant restrictions, or source IP restoration, leaving significant security controls ineffective.

Remediation

• Enable and configure the Microsoft traffic profile. For more information, see Enable Microsoft traffic profile.
• Deploy the Global Secure Access client to all managed devices. For more information, see Deploy Global Secure Access client.
• Review and configure traffic forwarding rules appropriately. For more information, see Review traffic forwarding rules.

Run it

The check runs as part of the whole assessment, with the ZeroTrustAssessment module installed:

Install-Module ZeroTrustAssessment -Scope CurrentUser
Connect-Maester
Invoke-Maester -Pack ZTA -SkipBuiltIn

Leave out -SkipBuiltIn to run Maester’s own checks in the same run.

About this check

Severity	High
Effort to fix	Medium
Impact on users	Low
Pillar	Network
Category	Network security
Product	Entra ID
Feature	Global Secure Access
Area	Access control
Licence	Entra_Premium_Private_Access, Entra_Premium_Internet_Access, Entra_Suite
Tenant	Workforce

Product, feature, area and ATT&CK are Maester’s: the assessment does not record them, so Maester keeps them in the pack’s taxonomy.json.

A Microsoft check, part of the Zero Trust Assessment pack. Text from ZeroTrustAssessment 3.1.0, © Microsoft, MIT licence.