What caused the sudden spike in false positive alerts from Lacework's File Integrity Monitoring (FIM) system yesterday?

Introduction

The sudden spike in false positive alerts from Lacework's File Integrity Monitoring (FIM) system yesterday presents a critical issue that requires immediate attention and thorough analysis. To address this problem, I'll employ a systematic approach to identify, validate, and resolve the root cause while considering both short-term fixes and long-term implications for our product ecosystem.

Step 1

Clarifying Questions (3 minutes)

• Looking at the timing, I'm thinking this could be related to a recent system update. Has there been any recent changes to the FIM system or related components?

Why it matters: Recent changes often correlate with sudden performance shifts. Expected answer: Yes, a minor update was deployed yesterday morning. Impact on approach: If confirmed, we'd focus on the update's contents and rollout process.

• Considering the nature of false positives, I'm wondering about the specificity of these alerts. Can you provide more details on the types of false positives we're seeing?

Why it matters: Different types of false positives may point to distinct root causes. Expected answer: The false positives are primarily related to benign system file changes. Impact on approach: This would guide our investigation towards system file monitoring logic.

• Given the sudden nature of the spike, I'm curious about the scale. What's the percentage increase in false positives compared to our baseline?

Why it matters: The magnitude of the increase helps prioritize the issue and narrow down potential causes. Expected answer: We've seen a 500% increase in false positives. Impact on approach: A dramatic increase would suggest a systemic issue rather than gradual degradation.

• Thinking about potential external factors, have there been any significant changes in customer environments or usage patterns?

Why it matters: External changes could trigger unexpected behavior in our system. Expected answer: No significant changes reported from major customers. Impact on approach: This would shift our focus more towards internal factors.