Incident Response for Compromised Device on Wireless
A retail company has 500 stores, each with Aruba APs and a local Mobility Controller (MD) managed by a central Mobility Master (MM). ClearPass is used for guest and employee access. The security team detected anomalous traffic from a employee laptop (MAC 00:1A:2B:3C:4D:5E) connecting to a known malicious IP. The laptop authenticated via 802.1X with EAP-TLS yesterday and was assigned the Employee role with full access. The team wants to isolate the device immediately, investigate, and remediate. They have Aruba ClearPass, Aruba Mobility Controllers, and Aruba Central for monitoring. The company policy requires that any compromised device be quarantined within 5 minutes and that the incident be documented with audit trails. The security team is remote and needs to execute the response using automation where possible.
1. Outline the steps to isolate the compromised device using ClearPass and Aruba infrastructure, including how to automate the quarantine and ensure audit trails.
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Immediate Isolation:
- Identify the device: Use Aruba Central or controller CLI to locate the client MAC 00:1A:2B:3C:4D:5E and its current session. Verify the user and role.
- Quarantine via ClearPass: In ClearPass, add the MAC to a static blacklist endpoint group (e.g., Quarantine-Endpoints). Modify the enforcement policy for the Employee service to check if the endpoint is in the Quarantine group; if so, assign a Quarantine role with restricted access (e.g., only remediation VLAN). Alternatively, use ClearPass to send a RADIUS CoA (Change of Authorization) to the controller to reauthenticate the client and apply the quarantine role.
- Automation: Use ClearPass REST API to add the MAC to the quarantine group and trigger a CoA. This can be scripted (e.g., Python) or integrated with a SIEM/SOAR platform. For example, a SOAR playbook can call ClearPass API to quarantine and then create a ticket.
- Controller action: If ClearPass CoA is not immediate, manually disconnect the client from the controller (using CLI or GUI) to force reauthentication. The client will reconnect and be assigned the quarantine role.
- Network containment: On the controller, apply a temporary ACL to block the MAC or assign a quarantine VLAN. For wireless, you can also use Aruba's built-in role-based ACLs.
Audit Trails:
- ClearPass logs all authentication and CoA events in Access Tracker. Ensure the quarantine action is logged with the administrator and reason.
- Aruba controllers log client disconnects and role changes. Forward logs to a SIEM.
- Use Aruba Central's audit logs for configuration changes.
- Document the incident in a ticketing system with timestamps and actions taken.
Investigation and Remediation:
- While quarantined, collect forensic data from the device (remote via EDR).
- After remediation, remove the MAC from the quarantine group and allow reauthentication. Update endpoint profile if needed.
Time constraint: Automation via API can achieve quarantine within 5 minutes. Pre-configure the quarantine group and enforcement policy to streamline.
2. How would you use Aruba Central and ClearPass to investigate the scope of the compromise and identify other potentially affected devices, and what preventive measures would you recommend?
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Investigation using Aruba Central and ClearPass:
- Aruba Central: Use the client monitoring and traffic analysis features to view the compromised device's traffic history. Check for connections to the malicious IP and identify other clients communicating with the same IP or exhibiting similar behavior. Use Central's alerts and reports to search for the IP across all sites.
- ClearPass: In Access Tracker, search for authentications from the compromised device's MAC and user. Look for patterns: did the device authenticate from unusual locations? Were there failed attempts? Check the endpoint profile to see if the device's posture changed. Use ClearPass Insight to create a report of all devices authenticated with the same user account or in the same role, and cross-reference with threat intelligence.
- Correlation: Export logs from both systems to a SIEM and correlate events. Look for lateral movement indicators, such as the compromised user accessing other devices or unusual RADIUS requests.
Preventive Measures:
- Implement ClearPass OnGuard or third-party EDR integration for posture assessment; require healthy devices for full access.
- Enable threat detection features on Aruba controllers (e.g., IDS/IPS) and integrate with ClearPass for automated threat response (e.g., using ClearPass's Threat Defense integration).
- Segment network access based on role and device type; limit lateral movement with micro-segmentation (Dynamic Segmentation).
- Enforce certificate-based authentication with strong revocation checking; ensure compromised device certificates are revoked promptly.
- Conduct regular security awareness training and simulate phishing attacks.
- Use Aruba Central's AIOps to detect anomalies and alert on unusual traffic patterns.
- Implement a formal incident response plan with automated playbooks (SOAR) for quarantine and investigation.
By leveraging both platforms, you can quickly scope the incident and harden the environment.