Endpoint detection and response (EDR) is software that continuously collects telemetry from devices to detect, investigate and contain threats before they spread. It gives security teams earlier warning of suspicious activity, the forensic detail needed to understand what happened, and the ability to isolate a compromised device remotely. This guide explains how EDR fits with your SOC, SIEM and MDR arrangements, and what to check before you choose a solution.
TL;DR:
- Keep antivirus for prevention; EDR adds investigation and containment after threats bypass it, while XDR correlates endpoint data with network, cloud, and identity activity.
- Automate containment only for high confidence detections; route other alerts to analysts because aggressive rules can disconnect legitimate servers or stop essential processes.
- Integrate EDR with SIEM logs, asset inventories, and identity systems to connect endpoint alerts to wider incidents; MDR can provide analyst coverage beyond office hours.
- Pilot the platform against defined metrics for detection coverage, false positives, and containment time, and test device isolation before full deployment.
- Review sensor health regularly because agents that stop reporting create blind spots dashboards can mistake for a quiet day.
Table of Contents
- What is endpoint detection and response (EDR)?
- How EDR works: continuous monitoring, detection, investigation and response
- Key capabilities and features to expect from modern EDR
- How EDR compares with antivirus (EPP) and with XDR
- Common use cases where EDR demonstrably helps
- Deploying and operating EDR: integration, staffing and practical constraints
- How to choose an EDR and immediate next steps
- Lancast perspective on EDR and managed security
- Lancast managed services that support EDR outcomes
- FAQ
- Sources
What is endpoint detection and response (EDR)?
EDR covers the workstations, servers and mobile devices that make up your organisation’s estate, continuously recording what happens on each one. Rather than scanning files against known threats, it builds a detailed record of activity so analysts can spot patterns that indicate compromise, even when no single event looks alarming on its own.
That telemetry typically includes:
- Process creation events, showing what programs started and what launched them
- Network connections, including destinations and ports used by each process
- System and registry changes that might indicate persistence or tampering
- Memory and file artefacts collected for later forensic analysis
Legacy antivirus works differently. It focuses on prevention, blocking known malicious files before they execute. EDR assumes some threats will get past prevention and gives you the visibility to catch them afterwards, which is why device security guidance treats EDR as a supplement to antivirus rather than a replacement for it.
How EDR works: continuous monitoring, detection, investigation and response
EDR operates as a loop, not a one-off scan. A lightweight agent on each endpoint streams activity data to a management console or cloud service in near real time, and the Cyber Incident Response technical standard sets this expectation explicitly for assured providers, requiring near real-time collection of process creation, network activity and system changes.
Detections are generated through several methods working together: known-bad signatures for established malware, behavioural analytics that flag suspicious sequences of actions, anomaly detection that compares current activity against a baseline, and correlation rules that tie several weak signals into one strong alert.
Once an alert fires, investigation tools let analysts work backwards through the timeline:
- Query historical telemetry to see what a process did before and after the alert
- Build a process tree showing parent-child relationships between programs
- Pull memory or disk artefacts for deeper forensic examination
- Cross-reference activity against other endpoints to check for lateral movement
Response actions follow directly from that picture. An analyst might isolate a device from the network, kill a malicious process, quarantine a file, or roll back changes made during an attack. Some of this can be automated, but full automation carries risk: an overly aggressive rule can isolate a legitimate server or kill a business-critical process, so most mature SOCs keep a human in the loop for anything beyond low-risk, high-confidence actions.
Pro Tip: Start with automated containment only for your highest-confidence detection rules, and route everything else to analyst review until you have months of tuning data behind you.
Key capabilities and features to expect from modern EDR
A capable EDR platform does more than flag suspicious files. The features below are what separate a basic alerting tool from something that genuinely supports detection and response work:
- Behavioural detection and rich telemetry, covering process, network, file and registry activity across every monitored endpoint
- Automated investigation and response (AIR), with playbooks that can triage common alert types without waiting for an analyst
- Forensic capture, including memory imaging and a visual chain of events for incident reconstruction
- APIs and SIEM integration, so endpoint data feeds into a central view alongside network and identity logs
- Sensor health monitoring, tracking which devices are reporting correctly and which have gaps in coverage
That last point matters more than it sounds. An EDR agent that silently stops reporting on a subset of laptops creates a blind spot that looks, on a dashboard, identical to a quiet day. We cover practical steps for maintaining sensor health in EDR deployments separately, since it is one of the more common gaps in otherwise well-configured estates.
How EDR compares with antivirus (EPP) and with XDR
These three terms get used loosely, which causes real confusion when organisations are trying to work out what they already have and what they still need.
- Antivirus or EPP (Endpoint Protection Platform) focuses on prevention: blocking known malware and risky behaviour before it runs.
- EDR assumes some threats bypass prevention, so it adds continuous visibility and the tools to investigate and respond after the fact.
- XDR (Extended Detection and Response) pulls telemetry from endpoints, network, cloud and identity systems into one correlated view; EDR is usually the endpoint data source feeding into it.
- SIEM and MDR sit alongside all three: a SIEM centralises logs from multiple tools for analysis, and MDR provides the human analyst capacity to act on what EDR and SIEM surface around the clock.
Our own explainer on endpoint detection sets out how these layers typically combine in practice. None of these tools fully replaces another; they overlap by design, and most organisations end up running EPP for prevention, EDR for endpoint visibility and response, and either a SIEM or MDR arrangement to tie the picture together.
Common use cases where EDR demonstrably helps
EDR earns its place in a security stack through a handful of recurring scenarios:
- Ransomware containment, isolating an infected device and, in some cases, rolling back encrypted files before an attack spreads further
- Threat hunting, using stored telemetry to search for evasive activity that automated rules missed, as described in threat-hunting guidance
- Post-incident forensic investigation, reconstructing exactly what an attacker accessed, changed or exfiltrated
- Remote and hybrid endpoint monitoring, giving consistent visibility over laptops that rarely connect to a traditional office network
Deploying and operating EDR: integration, staffing and practical constraints
Buying EDR software is the easy part. Getting value from it depends on how it fits into the rest of your security operation.
- Deployment speed matters during an incident. The CIR technical standard expects assured providers to deploy EDR rapidly and support it around the clock, which gives a useful benchmark even for organisations not pursuing CIR assurance directly.
- Integration with SIEM, asset inventories and identity systems turns isolated endpoint alerts into correlated incidents rather than a stream of disconnected notifications.
- Threat hunting needs data visibility and the right skills, not just a tool; NCSC’s SOC guidance is explicit that EDR is not a standalone solution and depends on being embedded into wider monitoring and an incident response capability.
- Sensor coverage and alert triage need ongoing attention, since an agent that fails silently or a triage queue that backs up both quietly erode the value of the deployment.
Our six-step guide to continuous security monitoring sets out how to keep these processes running once the initial deployment is done.
Pro Tip: Review sensor coverage weekly after rollout, then monthly once numbers stabilise, rather than waiting for an incident to reveal a gap.
How to choose an EDR and immediate next steps
Before signing a contract, work through a short evaluation process so you are choosing on evidence rather than vendor claims.
- Assess telemetry depth: confirm the platform captures process, network, file and registry events, not just file-level scanning.
- Test response capabilities: isolate a test device, kill a test process and check how quickly and cleanly each action completes.
- Check integration options: verify the platform has APIs or native connectors for your SIEM, identity provider and asset inventory.
- Run a pilot with clear success criteria: track detection coverage, false-positive rate and time to contain over a defined pilot period.
- Ask vendors direct questions: how is licensing structured, what support hours are included, and is managed detection and response available as an add-on.
- Decide whether to pair EDR with MDR: if your team lacks around-the-clock analyst coverage, a managed arrangement closes that gap without requiring new hires.
Our article on what a cybersecurity services review should cover walks through a fuller version of this checklist for teams preparing a formal procurement.
Lancast perspective on EDR and managed security
EDR only delivers on its promise when it is wired into real monitoring and incident response, not left running as an isolated dashboard nobody checks. We tend to recommend a short pilot before full rollout, specifically to catch sensor coverage gaps and alert-tuning issues while the stakes are still low. Once live, we expect telemetry coverage to be reviewed on a schedule, not just after something goes wrong.
— Carl
Lancast managed services that support EDR outcomes
If your team has the EDR software but not the round-the-clock capacity to act on what it finds, that gap is exactly where managed services earn their keep. Our managed services cover proactive monitoring and day-to-day support.
We also offer the groundwork many organisations need before EDR delivers full value, including penetration testing and vulnerability management to identify weaknesses before an attacker does. A managed engagement typically includes:
- An initial assessment of your current endpoint coverage and existing tools
- A pilot phase with defined success metrics before full deployment
- Ongoing sensor health checks and alert triage as part of routine support
- Availability for containment actions when an incident occurs outside office hours
Our Silver, Gold and Platinum support plans are described on our managed services page. Get in touch to discuss which level of coverage fits your current setup.
FAQ
What is endpoint detection and response?
Endpoint detection and response (EDR) is software that continuously monitors devices such as laptops, servers and mobiles, collecting activity data to detect suspicious behaviour, support investigation and enable containment actions like isolating a device or killing a malicious process.
Is EDR better than antivirus?
EDR and antivirus serve different purposes rather than competing directly: antivirus focuses on preventing known malware from running, while EDR adds visibility and response capability for threats that get past prevention. NCSC device security guidance treats EDR as a supplement to antivirus, not a replacement for it.
What are the top EDR tools available?
Vendor comparison pages from research firms such as Gartner list several major platforms and their relative positioning, though rankings shift frequently and depend heavily on an organisation’s specific requirements. Rather than chasing a fixed list, we recommend evaluating candidates against your own telemetry, integration and response needs as set out in our choosing guide above.
What is an example of EDR in use?
A typical example is ransomware detection: EDR identifies unusual file encryption activity on a device, isolates that device from the network automatically or on analyst command, and gives the security team the process history needed to trace how the attack started. This combination of detection, containment and forensic context is what threat-hunting guidance points to when describing EDR as a core data source for proactive investigation.
Sources
- Building a Security Operations Centre (SOC)
- Detecting the Unknown – A Guide to Threat Hunting
- Cyber Incident Response (CIR) Technical Standard (Level 2) v1.5