Defensive Strategies for TA0008

1. Application Access Token (T1550.001)

Defenses:

  • Token Security:

    • Rotate and revoke tokens periodically, especially after a potential breach.

    • Use Azure Managed Identities for secure token management.

    • Restrict token scope to the minimum permissions required (Principle of Least Privilege).

  • Conditional Access:

    • Implement policies to ensure that tokens are only issued to compliant devices and trusted locations.

    • Enforce MFA for token issuance where possible.

  • Audit and Monitoring:

    • Use Azure Monitor or Microsoft Sentinel to track unusual API calls or token activity via logs such as Azure AD Sign-ins and Application logs.

2. Pass the Hash (T1550.002)

Defenses:

  • Disable NTLM:

    • Where feasible, disable NTLM authentication entirely using Group Policy and enforce Kerberos instead.

  • Credential Protection:

    • Enable Credential Guard on Windows to prevent attackers from extracting password hashes.

    • Regularly reset passwords for accounts synchronized between on-premises AD and Entra ID.

  • Privileged Account Management:

    • Use Azure Privileged Identity Management (PIM) to limit exposure of privileged accounts.

  • Monitoring:

    • Analyze sign-ins and authentication patterns for anomalies, focusing on NTLM authentications.

3. Pass the Ticket (T1550.003)

Defenses:

  • Kerberos Ticket Expiry:

    • Reduce Kerberos ticket lifetimes to limit the viability of stolen tickets.

  • Service Account Hardening:

    • Ensure SPNs (Service Principal Names) are secured and constrained to specific purposes.

  • Privileged Account Segmentation:

    • Use separate accounts for administrative tasks and day-to-day operations to reduce ticket exposure.

  • Monitoring and Detection:

    • Enable logging for Kerberos events (Event ID 4769, 4768) and monitor for anomalies such as tickets issued to unauthorized systems.

Defenses:

  • Session Security:

    • Enforce short session lifetimes and require frequent re-authentication for sensitive accounts.

    • Use HTTP-only, Secure, and SameSite attributes for cookies to reduce client-side tampering and cross-site attacks.

  • Zero Trust Enforcement:

    • Leverage continuous access evaluation (CAE) in Azure AD to monitor for unusual session activities and enforce token revocation dynamically.

  • Browser Security:

    • Encourage users to avoid public or untrusted devices and clear sessions after use.

    • Deploy Microsoft Defender SmartScreen or similar tools to prevent phishing that may steal cookies.

  • Advanced Threat Detection:

    • Use Microsoft Defender for Identity to detect anomalous browser patterns or cookie reuse from unexpected geographies or devices.

Defenses Across Sub-techniques

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