The Role of Runtime Monitoring in Container Security

In the race to deploy modern applications faster and more frequently, containers have become the backbone of cloud-native development. But with this agility comes complexity and risk. Containers may be lightweight and portable, but they are also opaque by nature, often bundled with vulnerabilities, misconfigurations, or even malicious code. That’s why container security must evolve beyond traditional scanning.

Container scanning tools help identify risks during development, but they can only go so far. Once containers are running in production, static analysis can’t tell you which vulnerabilities are truly exploitable or how an attacker might behave in real time. That’s where runtime monitoring steps in, giving security and DevOps teams the visibility they need to defend actively running workloads.

In this Q&A, we explore the crucial role of runtime monitoring in container security to bring static and dynamic insights into a unified view and why this integrated approach is transforming DevOps security for organizations embracing containers at scale.

Q: Why is runtime monitoring so important for container security?

A:
Runtime monitoring is essential because it gives security teams visibility into how applications behave once they’re actually running. Containers are often treated as black boxes – packaged up, shipped off, and deployed across cloud-native infrastructure. But what happens during runtime can’t always be predicted by static scans alone.

While container scanning tools identify known vulnerabilities in base images and dependencies, they don’t show whether those vulnerabilities are ever actually used or exploited. That’s where runtime monitoring comes in. It detects anomalies like unexpected system calls, suspicious process activity, or unauthorized network communication—all in real time—and feeds that insight back to developers. This feedback loop helps expedite resolution by enabling faster response to real threats.

Q: How does this fit into a modern container security strategy?

A:
A complete container security strategy spans the entire application lifecycle:

1. Development – Scan code, dependencies, and base images using container scanning tools.
2. CI/CD pipelines – Integrate scans into builds, blocking vulnerable images from reaching production.
3. Deployment – Use runtime monitoring to detect and remediate vulnerabilities in containers in production.
4. Runtime Feedback – Correlate real-time behavior with scan data for smarter prioritization.
5. Continuous Improvement – Feed runtime insights back into the development cycle.

This loop turns container security into an ongoing, adaptive process aligned with the speed and complexity of modern DevOps environments.

Q: What are the limitations of static container scanning?

A:
Static container scanning tools are excellent at identifying vulnerabilities in code, third-party libraries, and base images before deployment. Checkmarx, for example, scans across all image layers – base, code, and dependencies – and provides remediation guidance early in the software development life cycle (SDLC).

However, there are key limitations:

• Static scans can’t detect runtime behavior like process injection or privilege escalation.
• They lack context, treating every CVE as high-priority without knowing if it’s even used.
• They produce high volumes of alerts without clear prioritization, contributing to alert fatigue for DevOps security teams.

Checkmarx addresses these issues by integrating with runtime monitoring tools like Sysdig, enabling teams to distinguish between theoretical vulnerabilities and those that are actively exploitable.

Q: How does runtime monitoring complement container scanning?

A:
Runtime monitoring closes the loop. It lets teams see which packages and libraries are being used in production and whether any of them are involved in suspicious activity. This is especially useful when you’re dealing with container images that include dozens of third-party components.

With Checkmarx and Sysdig working together, static scan data is enriched by runtime usage data. This correlation helps teams:

• Prioritize vulnerabilities based on execution at runtime.
• Reduce noise by eliminating non-exploitable findings.
• Speed up triage and remediation by focusing on what matters most.
• Create a feedback loop between code running in production and developer environments (e.g., IDEs), enabling rapid prioritization and faster resolution of exploitable vulnerabilities.

Instead of chasing every CVE, security teams can target the ones that are actually active in live environments.

Q: Can you give an example of how runtime monitoring improves DevOps security?

A:
Let’s say a developer builds a container with 25 vulnerabilities flagged by a container scanning tool. Without runtime insight, all 25 might seem equally urgent. But with monitoring the container in production, you learn that only five of those packages are actually executed, and only two of them make external network calls.

Now, you’re no longer spreading your attention thin. Your team focuses on the two exploitable vulnerabilities that are active, reducing risk and increasing efficiency. This is a major upgrade for DevOps security as it helps shift from reactive scanning to intelligent, risk-aware remediation.

Q: How does this integration support compliance and reporting?

A:
Many compliance frameworks like PCI-DSS, ISO 27001, and NIST require organizations to monitor runtime behavior and maintain security logs. The Checkmarx and Sysdig integration enables this in several ways:

• Runtime logs serve as evidence during audits or incident investigations.
• Scan Risk Reports summarize vulnerabilities by severity and runtime status, providing auditors with actionable documentation.
• Exportable formats (JSON, CSV, PDF) make it easy to integrate findings into compliance workflows.

This not only supports audit readiness but also strengthens overall container security posture by keeping security grounded in real-world data.

Q: How does this benefit developers?

A:
Developers want to move fast, but not at the expense of security. One of the biggest challenges is the overload of security alerts that don’t reflect reality. With runtime monitoring integrated into the process, developers:

• Get fewer false positives
• Receive contextual remediation advice
• Understand which issues are actually critical
• See how vulnerabilities are being used in production

Checkmarx even integrates with Docker and CI/CD pipelines, ensuring that developers receive real-time feedback without slowing down their workflows. As emphasized in the Container Security Checklist, empowering developers with context-aware insights leads to better security outcomes.

Q: What kind of runtime data is captured by Sysdig?

A:
Sysdig captures rich telemetry from running containers, including:

• Process executions
• File system access
• Network connections
• System calls and behaviors
• Container start/stop events

When integrated with Checkmarx, this data is used to confirm whether scanned vulnerabilities are associated with active components. This creates a feedback loop that ties runtime insights back into the static scanning process.

The result: fewer false positives, faster remediation, and higher confidence in container risk assessments.

From Static to Strategic

Runtime monitoring, when paired with robust container scanning tools, transforms security from a static checklist into a dynamic, responsive discipline.

By combining Checkmarx’s high-accuracy vulnerability detection with Sysdig’s real-time runtime analysis, organizations can prioritize real threats, reduce operational noise, and build truly secure containerized applications. It’s a smarter, faster, and more developer-friendly approach to DevOps security – one that’s ready for the scale of cloud-native development. Learn more about Checkmarx, Sysdig, and runtime insights in our joint webinar here.