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NASA·Software Engineer·Technical Phone Screen·Intermediate

Intermediate
May 2026

Summary

Interviewed for a security analyst role at NASA, got a scenario-based question about triaging a SIEM alert. Pretty focused interview, felt more like a practical walkthrough than a traditional Q&A.

Questions Asked (1)

Q1

You receive a SIEM alert for a suspicious login. What data sources would you use to confirm or rule out malicious activity?

Root Cause AnalysisSystem DesignTechnical Trade-offs
Author's notes

I started with auth logs and worked outward, endpoint telemetry, network flow data, threat intel feeds, maybe identity provider logs if it's SSO.

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AI HintsAI Generated

Suggested Approach

Start by outlining a systematic investigation process: gather evidence from multiple data sources to build a timeline, then correlate events to determine if the login is malicious. Emphasize that you would consider the context of NASA's environment, such as high-security requirements and potential nation-state threats.

Pro tip: Mention that you would also check for related alerts or anomalies in other systems, as a single suspicious login might be part of a larger attack. Additionally, highlight the importance of documenting your findings and following incident response procedures.

1. Identify the alert details

Review the SIEM alert to understand the user, source IP, timestamp, and any other relevant information. This will guide which data sources to query.

2. Check authentication logs

Examine authentication logs from the target system (e.g., Windows Event Logs, Linux auth.log) to verify the login attempt and see if it succeeded or failed.

3. Correlate with network data

Analyze network logs (firewall, proxy, NetFlow) to see if the source IP is known malicious, if there are other connections from that IP, and if data exfiltration occurred.

4. Examine endpoint activity

Look at endpoint detection and response (EDR) data or host-based logs to see what actions the user took after login, such as privilege escalation or file access.

5. Check identity and access management

Review IAM logs (e.g., Active Directory, Okta) for unusual group changes, MFA bypass, or other signs of account compromise.

Key Points to Mention

  • SIEM correlation rules and how to pivot from an alert to raw logs
  • Authentication logs (e.g., Windows Security Event ID 4624, 4625; Linux auth.log)
  • Network data sources (firewall, IDS/IPS, NetFlow, DNS logs)
  • Endpoint detection and response (EDR) telemetry
  • Identity and access management (IAM) logs and MFA status
  • Threat intelligence feeds to check IP/domain reputation

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.