Agent-Based vs. Agentless Security: Key Differences, Benefits, and Best Use Cases

When securing your cloud infrastructure, choosing the right approach for monitoring and protection is essential. Two major strategies in this domain are agent-based and agentless security. This blog explores these aspects in detail to help you make an informed decision for your organization’s cloud security risk management.

Understanding Agentless vs. Agent-based Security Approaches

Agent-based security requires installing a piece of software, called an agent, on each resource, like servers or virtual machines. This agent acts like a dedicated security guard that watches over the resource continuously. It collects detailed information about what’s happening on that resource, such as user activities, security events, and system performance. If the agent detects anything unusual—like someone trying to access data they shouldn’t—it can quickly alert the security team or even take action to stop the threat right away. Over time, as organizations started using cloud services, these agents were adapted to work in the cloud, becoming more sophisticated to keep up with the complex nature of modern cloud environments.

On the other hand, agentless cloud security operates without installing any software on individual resources. Instead, it uses APIs (Application Programming Interfaces) provided by cloud service providers. This method is similar to using security cameras that monitor multiple areas without needing to enter each room. By accessing data through these APIs, agentless systems can gather information about the security status of resources without putting any extra load on them. This approach is less intrusive, making it ideal for environments where performance is crucial, like applications that need to run smoothly without interruptions.

The evolution of these two methods reflects how organizations have adapted to the growing complexity of cloud technologies. Agent-based security provides detailed insights and control, particularly important in industries that handle sensitive data, like finance or healthcare. In contrast, agentless cloud security offers a more flexible and scalable solution, especially for organizations that use multiple cloud platforms. 

Understanding the practical differences between these two approaches can help businesses make informed decisions about protecting their valuable data and resources in the cloud.

Key Differences

Agent-Based Security:

1. Installation Requirement: Agent-based security involves installing a software agent on each resource—servers, containers, or virtual machines. This agent continuously collects data and monitors the resource for potential threats.
2. Data Collection: The agents provide detailed, real-time data directly from the monitored resources. This includes system metrics, security events, and application logs, deepening the resource’s security state.
3. Resource Impact: While agents offer comprehensive data, they can introduce a performance overhead on the resource. This is due to the additional processing required to gather and transmit security information.

Agentless Security:

1. Installation Requirement: Agentless endpoint security operates without deploying software on each resource. Instead, it uses cloud service provider APIs to gather security data and monitor the environment.
2. Data Collection: Data is collected through API integrations with cloud platforms, which provides a broader, less granular view of the security posture. This method is more focused on the overall environment rather than individual resources.
3. Resource Impact: Because it does not involve installing software on the resources, agentless data security minimizes any performance impact on the monitored workloads.

Benefits

Agent-Based Security:

1. In-Depth Visibility: Offers granular, real-time insights into each resource’s security posture. This includes detailed threat analysis and security metrics that are specific to the resource being monitored.
2. Real-Time Protection: Provides immediate detection and response to threats. This is particularly beneficial for environments where timely intervention is crucial to prevent breaches or mitigate attacks.
3. Customizable Policies: Allows for the creation of specific security policies tailored to each resource. This level of customization enhances control over security measures and compliance requirements.

Agentless Security:

1. Simplicity: Easier to deploy and manage because it eliminates the need to install and maintain agents on each resource. This reduces the operational complexity associated with resource monitoring.
2. Minimal Impact: Since it operates externally through APIs, there is no performance overhead on the resources being scanned. This makes it an ideal choice for high-performance environments where every bit of processing power counts.
3. Broad Coverage: Capable of providing visibility across multiple cloud platforms without altering existing infrastructure. This is especially useful for organizations with hybrid or multi-cloud environments.

Discovering and Protecting API Endpoints

As organizations increasingly rely on cloud environments, APIs (Application Programming Interfaces) have become crucial for integrating applications and microservices. However, this expansion in API usage also widens the attack surface, posing risks related to sensitive data exposure and effective monitoring. Securing these APIs is essential to maintaining a robust security posture. 

Let’s explore how both agent-based and agentless endpoint security approaches contribute to API security and how you can leverage these methods to safeguard your endpoints.

1. Increasing API Visibility in Your Deployment

Understanding and managing API security begins with visibility. Knowing which APIs are present and how they interact with your environment is critical for effective protection. Here’s how you can enhance API visibility:

• Agent-Based Discovery: By deploying agents like Prisma Cloud Defenders, you can create Web Application and API Security (WAAS) rules tailored for specific environments such as containers, hosts, or application-embedded systems. This method enables in-depth inspection of HTTP traffic and helps in identifying API endpoints with greater granularity.
• Agentless Discovery: In environments like AWS, you can use tools like VPC traffic mirroring to discover APIs without installing additional software on each resource. This approach relies on adding WAAS agentless rules to monitor traffic, allowing you to detect and manage API endpoints without the need for dedicated agents.

Steps to Enable API Discovery:

• Create WAAS Rules: Set up rules based on your specific deployment needs, whether for containers, hosts, or application environments.
• Verify Discovery: Ensure API Discovery is active and select Runtime Security on the Prisma Cloud switcher to start monitoring.
• Monitor Traffic: Use WAAS to track traffic for any malicious activity, such as web attacks, bot behavior, denial-of-service (DoS) attempts, unauthorized access, and sensitive data leaks.

2. Assessing the Risk Level of Discovered APIs

Once APIs are discovered, the next step is to assess their risk profiles. Understanding the potential risks associated with each API helps prioritize security measures. Here’s how to perform this assessment:

• API Inventory: Organize discovered API endpoints by domain name, services, or accounts. Evaluate risk factors such as internet accessibility, authentication gaps, exposure of sensitive data, and any past security incidents.
• Risk Prioritization: Group APIs based on their risk levels. This categorization enables security teams to focus on high-risk endpoints that may require immediate attention and protective measures.

Steps to Assess Risk:

• Review API Inventory: Examine the inventory for potential risks and categorize APIs according to their exposure and sensitivity.
• Prioritize Actions: Implement in-line protections for high-risk APIs while continuously monitoring lower-risk endpoints to manage overall security effectively.

3. Investigating Incidents and Suspicious Activity

Ongoing investigation is crucial for maintaining API security. Analyzing incidents helps identify vulnerabilities and refine security measures.

Here’s how you can investigate and respond to suspicious activity:

• Incident Review: Prisma Cloud’s WAAS analytics allow you to analyze events, inspect individual requests, and identify patterns or trends that may indicate vulnerabilities or malicious activity.
• Continuous Improvement: Use insights from these investigations to enhance your security measures. Regularly update your security policies based on findings to improve your overall cybersecurity posture.

Best Use Cases

Agent Based Security:

1. Highly Regulated Environments: In industries such as finance, healthcare, or government, where compliance with stringent security and regulatory requirements is critical, agent based security provides the detailed data and control needed to meet these standards.
2. Complex and High-Security Applications: For applications with sensitive data or critical operational roles, agent-based security offers deep visibility and real-time threat management, ensuring robust protection and immediate response capabilities.
3. Customizable Security Policies: Ideal for environments where specific security policies are required for different resources or applications. The ability to tailor policies to individual resources enhances the overall security posture and compliance.

Agentless Security:

1. Large-Scale Cloud Environments: For organizations with extensive cloud infrastructure, deploying agents on every resource can be impractical. Agentless security provides a scalable solution by leveraging API integrations to monitor and manage large environments effectively.
2. Multi-Cloud Strategies: Organizations operating across multiple cloud platforms benefit from agentless security’s ability to provide a unified view of security across different providers. This approach simplifies management and ensures consistent security policies across diverse environments.
3. Ease of Deployment: In scenarios where rapid deployment and minimal impact on resource performance are essential, agentless security is advantageous. Its simplicity and non-intrusive nature make it suitable for quickly scaling security measures without disrupting existing operations.

Final Word

Selecting between agent-based and agentless security methods requires careful consideration of your organization’s specific needs and environment. Agent-based security provides in-depth, real-time insights and protection, making it suitable for complex and highly regulated environments. Conversely, agentless security offers simplicity, broad coverage, and minimal resource impact, making it ideal for large-scale or multi-cloud environments. You can choose the best approach to your security strategy and operational requirements by understanding these key differences and benefits.