What is endpoint detection and response (EDR)?

Key takeaways

• EDR stands for endpoint detection and response and monitors devices for suspicious activity as it happens.
• Unlike traditional antivirus, EDR looks at behavior instead of relying only on a list of known threats.
• EDR helps contain suspicious files or processes and provides a record of how an attack happened and what it affected.
• EDR supports active threat detection, but it doesn’t replace backups or guarantee that every attack will be prevented.

Cybersecurity tools are difficult to compare when they all seem to solve similar problems. Antivirus, EDR, extended detection and response (XDR), and managed detection and response (MDR) all play a role in security, but they don’t provide the same type of protection.

In this guide, we’ll explain what EDR is, how it works, how it compares to other security options, and what to consider when choosing an EDR tool.

What is EDR?

EDR stands for endpoint detection and response. It’s a security tool that continuously monitors endpoints for suspicious activity. An endpoint is a device connected to a network, such as a laptop, phone, or server. EDR looks for behavior that indicates an attack, alerts you when something is wrong, and can help contain threats before they spread further.

For this article, we’ll focus mainly on EDR for servers; where businesses may store applications, files, customer information, and other important data.

The “detection and response” part refers to identifying suspicious activity and giving you the information and controls needed to respond.

How EDR works

EDR works by continuously monitoring activity on an endpoint to identify suspicious behavior, respond to threats, and keep a record of what happened. The process moves through four stages: collect, detect, contain, and investigate. 

Data collection

EDR uses a software program called an agent that’s installed on a server or device to collect information about its activity. This can include running processes, file changes, and network connections. That activity gives the EDR system a picture of what is happening on the endpoint over time.

Behavior analysis

The EDR system analyzes the activity it collects and compares it with normal behavior and known attack patterns. Analytics and machine learning help identify behavior that looks suspicious, even when it doesn’t match a known threat.

Immediate response

When suspicious activity is detected, EDR takes steps to limit it. Depending on the EDR tool and the type of attack, that includes quarantining a file or process so it can’t run, or isolating an affected device from the network. The goal is to help contain the activity before it spreads to other systems.

Investigation

EDR keeps a record of the activity surrounding the incident so you can investigate what happened, including how an attack started, what it affected, and how far it spread.

Key EDR capabilities

Although features vary by EDR tool, common capabilities include:

• Behavioral detection: Identifies activity that may indicate an attack
• Automatic containment: Quarantines suspicious files or processes
• Attack-chain reconstruction: Shows how an incident developed
• Real-time and historical visibility: Shows current and past activity
• Threat intelligence: Uses known threat and attack information
• Alerting: Notifies teams when suspicious activity is detected

EDR vs. traditional antivirus

The difference between EDR and traditional antivirus is that antivirus checks files against a list of known threats, while EDR watches how processes behave on a server and raises an alert when something acts like an attack, including threats no one has seen before. 

Some EDR platforms include traditional antivirus-style scanning along with behavioral monitoring, so one product can provide both types of protection. Running a separate antivirus product and EDR product on the same server can cause conflicts, so it’s generally better to use one endpoint security product on each server.

Comparison	Traditional antivirus	EDR
How it detects threats	Compares files and activity against known threats	Monitors behavior and activity for signs of an attack
What it can catch	Threats it already recognizes	Known threats and suspicious behavior that may not match a known threat
What you get after an alert	A warning that a known threat was detected	Context about what happened, what was affected, and how the incident developed
When it acts	When a known threat is identified	Detects and responds while suspicious activity is happening

Popular EDR tools and platforms

There are several popular EDR tools and platforms available. The right option depends on the tools and services you already use, your internal security resources, and how much of the setup and ongoing monitoring your team wants to manage.

CrowdStrike Falcon

CrowdStrike Falcon provides endpoint protection and EDR through its cloud-based Falcon platform. Its endpoint security tools focus on continuous monitoring, behavioral detection, investigation, and response. CrowdStrike also offers XDR and MDR services for organizations that want to extend protection beyond endpoints or add outside security support.

Microsoft Defender for Endpoint

Microsoft Defender for Endpoint is an enterprise endpoint security platform that helps organizations prevent, detect, investigate, and respond to threats across devices. It includes EDR, behavioral detection, automated investigation and response, tools for identifying security weaknesses, and integration with other Microsoft security tools.

SentinelOne Singularity

SentinelOne Singularity uses behavioral analysis to detect suspicious and malicious activity across endpoints. The platform includes automated containment and response capabilities and helps teams investigate and respond to threats. SentinelOne also supports broader visibility across areas such as user accounts, sign-in activity, and cloud environments. 

Platform	Best known for	Who typically runs it	What the buyer manages
CrowdStrike Falcon	Cloud-based endpoint detection, threat intelligence, and response	Security teams and IT teams	Deployment, configuration, alert review, investigation, and response unless managed services are added
Microsoft Defender for Endpoint	Endpoint security integrated with the broader Microsoft security environment	IT and security teams, especially those already using Microsoft products	Onboarding, policies, alert review, investigation, and response
SentinelOne Singularity	Behavioral detection and automated endpoint response	IT and security teams	Deployment, configuration, alert monitoring, investigation, and response

These platforms provide EDR capabilities, but they still require internal time and expertise to manage. You may prefer a managed option that reduces how much of that work falls on your staff. See how Acronis EDR from Nexcess works below.

EDR vs. XDR and MDR

EDR focuses on endpoints, while XDR and MDR build on that protection in different ways.

Extended detection and response (XDR) expands detection beyond endpoints to other parts of the environment, such as email, networks, cloud services, and identity systems that manage user accounts and access.

Managed detection and response (MDR) adds a service team that monitors alerts and helps investigate and respond to threats for you. 

EDR is often a practical first step for businesses that want more active threat detection before moving to broader XDR coverage or a managed MDR service. 

Security option	Scope	Who acts on the alert	Typical buyer
Antivirus	Individual endpoints	The user or IT team	Businesses looking for basic endpoint protection
EDR	Endpoint activity and behavior	The internal IT or security team	Businesses that need more visibility into endpoint threats
XDR	Endpoints plus areas such as email, networks, cloud, and identity	The internal IT or security team	Organizations that want broader visibility across their environment
MDR	Detection and response supported by a managed service team	The MDR provider works with the customer to investigate and respond	Businesses that want outside security expertise or don’t have a dedicated security team

Why businesses add EDR

Businesses add EDR because of a cyber insurance renewal, upcoming audit, or a customer security questionnaire asking how endpoints are monitored. 

Your organization may have backups in place to help protect data if something goes wrong. However, backups don’t tell you that an intrusion is happening, how it started, or what the attacker touched. EDR fills that gap by monitoring endpoint activity and providing information that can help you detect and investigate suspicious behavior. 

EDR doesn’t replace backup: EDR helps you detect and understand an incident, while backups give you a way to recover afterward.

What insurers and auditors are asking for

Cyber insurers, auditors, and other reviewers ask for proof that your business has active endpoint monitoring in place, not just a way to restore data after an incident. They also want evidence that suspicious activity can be detected, documented, and investigated. 

EDR provides evidence by recording detections and response activity. It can support insurance, audit, and compliance requirements, but it doesn’t guarantee that your business meets a specific standard or qualifies for coverage. Meeting those requirements remains your responsibility.

EDR use cases

EDR use cases stretch across finance, healthcare, and any business that takes security seriously. 

Credit unions and banks

If you’re part of a credit union or bank, an examiner or board member will ask how you would know if someone gained unauthorized access to your server. EDR provides a record of detected activity, what happened, and how the organization responded.

That information can support the institution’s existing information security program and provide evidence during reviews or examinations. It doesn’t replace your responsibility for meeting security and regulatory requirements. 

Healthcare and medical practices

If you’re part of a clinic, surgery center, or other healthcare organization, you’ll be asked who is monitoring your servers for suspicious activity and what evidence is available when something goes wrong.

EDR provides documented detection and response activity that supports a HIPAA-ready security approach and can be useful during audits or security assessments. You’re still responsible for meeting HIPAA requirements. 

Common EDR scenarios for any business

Businesses may also use EDR to:

• Detect behavior associated with ransomware activity.
• Investigate what happened after a server is compromised.
• Help contain suspicious activity before it spreads to other systems.
• Detect attacks based on behavior, including activity that may not involve a known malicious file.

Challenges and limits of EDR

EDR shows you more of what’s happening on your server and other endpoints, but someone still needs to monitor it. Depending on the business, an EDR platform may generate a high volume of alerts, which need to be reviewed to determine when action is necessary.

EDR also needs to be adjusted to fit the systems it protects. Activity that is normal for one server may be unusual for another, so alert settings should be refined. This can take time, particularly for businesses without a dedicated security team.

EDR doesn’t guarantee prevention. It helps identify and contain suspicious activity, but no EDR platform can guarantee that every attack will be detected or stopped. 

These challenges are one reason managed EDR options exist. They provide additional expertise for businesses that don’t have the internal staff or resources to manage endpoint security on their own.

What to look for in an EDR tool

EDR tools vary in how they detect threats, respond to incidents, and fit into your existing systems. When comparing options, consider how much work the EDR tool will require from your team to set up, monitor, and manage.

A few things to evaluate include:

• Behavioral detection: Does the tool monitor activity for suspicious behavior instead of relying only on known threats?
• Containment: Can it automatically quarantine suspicious files or processes or isolate an affected device?
• Investigation: Does it clearly explain what happened, what was affected, and how an incident developed?
• Alert routing: Where do alerts appear, and how will the right person know when something needs attention?
• Response responsibility: Who reviews alerts, investigates incidents, and takes action when a threat is detected?
• Deployment effort: What needs to be installed or configured, and how much ongoing management does the tool require?
• Data location: Where will your data be stored, and could choosing EDR now affect where future backups or related services are stored?

What does EDR cost?

EDR pricing varies by provider and is based on the number of endpoints or servers being protected. The cost also depends on the features included and whether monitoring or managed security services are part of the plan.

Acronis EDR from Nexcess

Acronis Endpoint Detection and Response from Nexcess adds real-time behavioral detection to help you identify suspicious activity while it’s happening. It can also reconstruct the attack chain so you can see how an attacker got in, what they touched, and how far the incident spread. 

Acronis EDR also includes:

• Behavior-based detection: Acronis EDR monitors activity on the server instead of relying only on a list of known threats. 
• One agent: Acronis EDR uses the same Acronis agent as Acronis Backup and Disaster Recovery. 
• One portal and one login: Alerts and incidents appear in the Nexcess portal, and one click takes you into the Acronis console for further investigation without a second login. 

For existing Acronis Backup or Disaster Recovery customers, turn on Acronis EDR. Nothing else changes. For businesses that don’t already use Acronis, EDR can serve as a first step into managed security. 

There is one important storage consideration to understand before ordering. If you add Acronis EDR before Acronis Backup, that server’s future Acronis Backup storage location will be set to Acronis Cloud. That choice is permanent for that machine. If you want a different backup storage location, order Acronis Backup with EDR from the start.

Talk to a solutions engineer about a security review or learn more about Acronis EDR from Nexcess.