Key Takeaways
- Agent-based security provides deep, real-time monitoring of workloads but requires deployment and maintenance on each host.
- Agentless security offers quick deployment and minimal performance impact, making it ideal for cloud configuration checks and compliance.
- Combining agent-based and agentless systems gives you holistic visibility, faster threat detection, and simplified cloud security management.
Understanding Agent-Based and Agentless Security: What You Need to Know
When you’re tasked with securing servers, cloud workloads, or hybrid environments, you’ve likely heard about agent-based and agentless security systems. You might be thinking, “Which one should I choose?” or “How do these approaches really differ in practice?” The truth is, both have their strengths and weaknesses, and your choice depends on your environment, priorities, and resources.
In this blog, we’ll explore agent vs agentless security, compare monitoring approaches, highlight pros and cons, and provide guidance on using them effectively for cloud workload protection and compliance.
What Are Agent-Based and Agentless Systems?
Agent-Based Systems
These require a small software program (an agent) on each device, server, or workload. The agent collects data locally and reports it to a central system. This gives you deep, real-time visibility into everything happening on the host.
Here’s the gist:
Agentless Systems
Agentless systems don’t touch the hosts. They rely on APIs, cloud-native connectors, or network scans to gather information remotely. You can deploy quickly, but the visibility is more limited — you’ll see configurations and network activity rather than internal processes.
Suppose you have 50 virtual machines in the cloud. An agentless system can start scanning all of them right away. With agent-based security, you’d first need to install and configure agents on each machine, which takes more time but gives you much deeper insight into what’s happening on each host.
- Designed for Hostile Environments
- Secure Architecture
- End the Security Tax
How Agent-Based and Agentless Security Differ
Lets break it down:
| Feature | Agent-Based Security | Agentless Security |
|---|---|---|
| Installation | Software must be installed on each host | No installation; uses APIs or network scans |
| Monitoring Depth | Deep insight into logs, processes, and system events | Limited to configurations, logs, and network data |
| Performance Impact | Uses CPU and memory; may slow the system | Minimal; no software runs locally |
| Real-Time Alerts | Immediate alerts possible | Mostly relies on scheduled scans |
| Deployment Speed | Slower; each host needs an agent | Fast; connect remotely without touching hosts |
| Maintenance | Each agent needs updates and patches | Less maintenance; mainly cloud platform updates |
Example: If a vulnerability is discovered on a production server, an agent-based system might alert you immediately. An agentless scan may only catch it during the next scheduled scan.
Pros and Cons of Agent-Based Systems
Agent-based systems offer powerful monitoring, but they aren’t without trade-offs.
Pros:
- Deep monitoring of workloads for runtime activity and security events.
- Real-time alerts enable quicker incident response.
- Direct enforcement of security policies on hosts.
Cons:
- Resource-intensive; agents use CPU, memory, and storage.
- Deployment can be time-consuming, especially at scale.
- Maintenance overhead, with frequent updates required.
Pros and Cons of Agentless Systems
Agentless systems are simpler and quicker to deploy, but you do sacrifice some depth.
Pros:
- Quick deployment across multiple cloud accounts or devices.
- Minimal impact on system performance.
- Lower maintenance effort.
Cons:
- Limited depth; runtime activities are harder to monitor.
- Real-time monitoring is limited; mostly scheduled scans.
- Dependent on APIs and network visibility.
Pro Tip: You want to ensure compliance across multiple cloud accounts. An agentless scan can quickly identify misconfigured storage buckets or network settings. However, it won’t catch processes behaving abnormally on a server — that’s where agents come in.
Agent-Based vs Agentless Scanning in Cloud Security: Which is Better?
Cloud security adds extra challenges. You want to protect workloads, monitor configurations, and detect threats without affecting system performance. Here’s how the two approaches compare in a cloud context:
| Aspect | Agent-Based Scanning | Agentless Cloud Security |
|---|---|---|
| Deployment Speed | Slower; each workload needs an agent | Quick; uses cloud-native APIs or connectors |
| CSPM (Cloud Security Posture Management) | Requires agents to gather workload details | Directly integrates with cloud provider APIs |
| Visibility | Deep, per-host monitoring | Limited to what the API exposes |
| Workload Protection | Monitors runtime threats | Focuses on configurations and network-level security |
| Maintenance | Updates needed for each agent | Centralized, minimal upkeep |
Example: To ensure AWS and Azure workloads are compliant, an agentless CSPM tool can quickly scan all accounts. For runtime threat protection on production servers, agents provide deeper visibility.
When to Use Agent-Based vs Agentless Security?
Here’s how to think about choosing:
Agent-Based Security
- Choose this if you need deep runtime monitoring.
- Real-time alerts and incident response are critical.
- You have resources to deploy and maintain agents.
Agentless Security
- Ideal if you need quick coverage across multiple cloud accounts.
- System performance is a concern.
- Focused primarily on compliance checks and configuration monitoring.
Pro Tip: In a hybrid environment, you could install agents on on-prem production servers for real-time monitoring and use agentless scanning for cloud workloads to get fast insights into configurations.
Combining Agent-Based and Agentless Approaches
Often, the best solution is both together. Agentless scanning gives broad coverage quickly, and agent-based monitoring provides depth where needed.
| Benefit | How It Helps |
|---|---|
| Holistic Coverage | Agentless covers many workloads fast; agents provide deep visibility for critical hosts |
| Reduced Blind Spots | Misconfigurations identified by agentless scans; runtime threats detected by agents |
| Flexible Deployment | Install agents only where necessary to save resources |
| Faster Incident Response | Cross-validation between agentless and agent-based alerts improves prioritization |
Example: If an agentless scan finds a misconfigured cloud storage bucket, the agent on a critical server accessing it can monitor activity in real-time and prevent misuse.
Considerations for Selecting a Cloud Security Product
As you’re assessing products, evaluate:
- Workload Type: Are you monitoring VMs, containers, or serverless functions?
- Deployment Timing: What is your timeline for coverage?
- Manageability: Do you have the bandwidth to provide management of your agents?
- Objectives: Are you focused on compliance, runtime protection, or both?
Most new cloud security solutions will offer a hybrid solution comprised of agentless scanning (for compliance and rapid deployment) and agents for runtime threat protection.
Next Steps to Implementing Your Security
- Evaluate Your Environment: Understand which workloads require deep monitoring, and for which you can take an agentless approach.
- Perform Agentless Scans First: To get started quickly, you'll want to identify misconfigurations across your cloud accounts.
- Agent Installation of Critical Workloads: We recommend using agent-based security for comprehensive detection of threats and enforcement of security policies that will require continual analysis of workload runtime attributes.
- Combine Strategies: You can now leverage observations made from agentless and agent-based security, typically when declaring a security threat and/or false positive activity.
- Continuous Monitoring: Over time, track cloud entitlements, (mis)configurations, and runtime threats.
Pro tip: Begin with an agentless CSPM scan on any/all your cloud accounts, then install agents on production servers and work towards the continuous detection of runtime threats.
Securing your cloud and hybrid environments doesn’t have to be complicated. By understanding the differences between agent-based and agentless security—and knowing how to use both effectively—you can gain deeper visibility, faster threat detection, and simpler compliance management.
Fidelis Security is here to help you every step of the way. Whether you want to start with quick agentless scans or deploy agents for critical workloads, we provide the tools and expertise to protect your environment comprehensively.
Take the next step today: Book a Demo to see Fidelis Security in action, or Contact Us to speak with our experts and find the right solution for your organization. Your cloud security journey starts here.
