Scenario: Pass-the-Hash (PtH) Attack Detected and Contained Using XDR

April 2025

A Pass-the-Hash (PtH) attack occurs when an attacker uses stolen password hashes to authenticate as a user without needing the plaintext password. This technique exploits the NTLM authentication protocol and enables lateral movement across a network. Early detection and response are critical to prevent privilege escalation and data theft.

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1. Initial Threat Detection

• Endpoint security sensors detect a privileged user account making rapid authentication attempts across multiple devices.

• Network intrusion detection systems (IDS) flag unusual NTLM authentication traffic originating from an admin workstation targeting domain controllers.

• XDR correlates these activities, identifying the behavior as a Pass-the-Hash (PtH) attack, where an attacker exploits stolen password hashes instead of plaintext credentials.

Detection Sources

1. Endpoint Logs:

   • Suspicious authentication requests using NTLM hashes instead of traditional passwords.

   • Unexpected access attempts by privileged accounts on unfamiliar machines.

2. Network Traffic Analysis:

   • Lateral movement inside the network without conventional authentication.

   • SMB and WMI connections initiated from non-administrative endpoints.

3. Identity Access Logs:

   • Privileged accounts authenticating on multiple systems without prior logon history.

   • Sudden escalation of privileges without an associated authorization request.

4. Domain Controller Logs:

   • Track NTLM authentication events, specifically:

     • Event ID 4624: Successful logon.

     • Event ID 4648: Logon using explicit credentials.

     • Event ID 4672: Privileged account logon.

5. Threat Intelligence Integration:

   • Matches detected behavior against known PtH attack patterns in external intelligence feeds.

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2. Data Collection & Correlation

• XDR aggregates logs across multiple security domains:

  • Endpoint activity: Tracks NTLM authentication attempts, account behaviors, and execution of credential dumping tools.

  • Network logs: Detects SMB and WMI usage patterns related to lateral movement.

  • Identity logs: Identifies anomalies in privileged access attempts.

  • Threat intelligence feeds: Cross-references detected behaviors with known PtH attack indicators.

• Machine learning-based threat correlation helps reconstruct the attack timeline, pinpointing the source of credential compromise.

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3. Automated Response Actions

1. Block Further Authentication Attempts:

   • Prevents the compromised credentials from being used to escalate access.

2. Endpoint Isolation:

   • Disconnects affected machines to contain lateral movement.

3. Account Lockdown & Reset:

   • Disables the compromised privileged accounts and enforces an immediate password reset.

4. Security Team Alert:

   • XDR generates high-fidelity forensic alerts, providing detailed remediation steps.

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4. Investigation & Remediation

Steps:

1. Trace the attack source:

   • Identify how credential hashes were stolen (e.g., Mimikatz execution, LSASS memory scraping).

2. Forensic Analysis:

   • Examine affected endpoints for remnants of credential-dumping tools.

3. Privilege Audit:

   • Review account escalation paths and authentication anomalies.

4. Network Review:

   • Analyze SMB/WMI communication logs for additional compromised machines.

Mitigation & Hardening:

1. Implement Strong Authentication Mechanisms:

   • Enforce Kerberos authentication and multifactor authentication (MFA) for privileged accounts.

2. Enable Credential Guard:

   • Protect LSASS.exe from unauthorized memory access.

3. Restrict NTLM Usage:

   • Disable NTLM authentication where possible to eliminate PtH risks.

4. Deploy Advanced Monitoring:

   • Configure real-time detection rules for abnormal NTLM authentication patterns.

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Outcome

✅ PtH attack detected and neutralized before domain-wide compromise. ✅ Compromised credentials revoked, preventing further unauthorized access. ✅ Security policies hardened to eliminate future PtH vulnerabilities. ✅ XDR delivers real-time insights to enhance detection strategies.

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This refined version showcases how XDR enables proactive threat hunting, automated containment, and forensic analysis, allowing organizations to swiftly mitigate Pass-the-Hash attacks. 😊