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Transport Layer Security (TLS) inspection is a critical capability for modern cybersecurity, allowing organizations to decrypt and analyze encrypted traffic for threats like malware, data exfiltration, and other malicious activities. Microsoft’s Entra Internet Access now offers TLS inspection in preview, enhancing visibility and security controls for encrypted communications.
You Should Know:
1. How TLS Inspection Works
TLS inspection decrypts traffic at the perimeter, inspects it for threats, and re-encrypts it before forwarding it to the destination. This ensures:
– Malware Detection – Identifies hidden threats in encrypted traffic.
– Data Loss Prevention (DLP) – Monitors for sensitive data leaks.
– Compliance Enforcement – Ensures traffic adheres to security policies.
2. Configuring TLS Inspection in Entra Internet Access
To enable TLS inspection, follow these steps:
Step 1: Access Entra Admin Portal
Connect-AzureAD
Navigate to Security > Entra Internet Access.
Step 2: Enable TLS Inspection (Preview)
Set-EntraTLSInspection -Enable $true -PolicyName "StrictInspectionPolicy"
Step 3: Deploy Certificate Authority (CA) for Decryption
openssl req -new -x509 -keyout ca.key -out ca.crt -days 365 -nodes
Upload the CA certificate to Entra:
Import-EntraCertificate -CertificatePath "C:\ca.crt" -Purpose "TLSInspection"
Step 4: Apply Inspection Policies
New-EntraTLSInspectionRule -Name "BlockMalwareTraffic" -Action Block -ThreatType "Malware"
3. Verify TLS Inspection
Check decrypted traffic logs:
Get-EntraTrafficLog -Filter "TLSInspectionStatus eq 'Decrypted'"
4. Bypass Inspection for Trusted Domains
To exclude trusted sites (e.g., banking portals):
New-EntraTLSInspectionExclusion -Domain "banking.example.com"
5. Monitor & Troubleshoot
Use Microsoft Sentinel for advanced threat detection:
SecureInternetAccess | where TLSInspectionResult == "MalwareDetected"
What Undercode Say
TLS inspection is a game-changer for enterprise security, but it must be implemented carefully to avoid privacy concerns. Always:
– Whitelist sensitive domains (e.g., healthcare, finance).
– Monitor performance impact (decryption adds latency).
– Rotate CA certificates regularly to prevent MITM risks.
For deeper security, combine TLS inspection with:
Linux: Inspect decrypted traffic with tcpdump sudo tcpdump -i eth0 -A -s 0 'tcp port 443'
Windows: Check SSL/TLS handshake events Get-WinEvent -LogName "Microsoft-Windows-TLS/Operational"
Expected Output:
- Decrypted traffic logs in Entra Admin Portal.
- Blocked malware attempts visible in Microsoft Defender.
- Improved DLP compliance reports.
Prediction
As TLS inspection becomes mainstream, expect:
- More AI-driven decryption policies (auto-whitelisting safe traffic).
- Tighter regulatory scrutiny on decryption practices.
- Enhanced adversarial evasion techniques (e.g., encrypted malware using AI).
Relevant URLs:
IT/Security Reporter URL:
Reported By: Markolauren Entrasse – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
