Endpoint protection choices often involve three terms: EDR, XDR and MDR. Vendors use them differently and boundaries vary. Product names alone are insufficient: what matters is what the solution does and who will operate it.
EDR: endpoint detection and response
An Endpoint Detection and Response agent monitors computers or servers: processes, file changes, network connections and logins. It identifies suspicious behaviour beyond known malware signatures.
Typical capabilities include:
- Detecting suspicious behaviour and related activity.
- Recording events for retrospective incident investigation.
- Responding through device isolation or process termination.
- In some products, reversing changes after an attack.
EDR still needs people to assess alerts, distinguish false positives and approve action. Without them, much of its value remains unused.
Verify compatibility with existing antivirus and critical applications. Two protection products can conflict, so migration usually proceeds gradually.
XDR: context across multiple sources
Extended Detection and Response extends visibility beyond endpoints, combining data from email, identities, cloud, networks or firewalls. This connects events that one source cannot explain, such as suspicious login followed by unusual server activity.
Coverage varies. Some products primarily integrate their own modules; others accept third-party data. Check:
- Which sources are supported in your environment.
- Whether integrations are included or licensed separately.
- Retention periods and data access.
- How alerts combine into an incident.
Broader coverage produces more data. Without clear ownership, it may create more alerts rather than better visibility.
MDR: a managed service
Managed Detection and Response is a service. Provider analysts monitor your alerts, assess them and respond or notify you as agreed. Services using multiple sources are sometimes called MXDR.
Vendors and specialist providers offer MDR. Examples include SentinelOne and Heimdal. Their terms define scope, availability and responsibilities. These are vendor services, separate from standard APPSEC deployment support.
Read the contract carefully:
- What may analysts do independently and what requires approval?
- How, to whom and how quickly are incidents reported?
- Does coverage extend beyond endpoints?
- Who handles recovery and forensics?
- Which tasks remain with your team?
You still need a contact person, authority over operational interventions and a recovery process.
Choose around your situation
The key question is who assesses alerts and when. Consider a serious server alert on Saturday night: who sees it, who approves response and how does management hear about it?
- Small businesses without security specialists often benefit from simpler management and one console. EDR plus a managed service may fit their risks and budget.
- Medium-sized businesses with IT teams may operate EDR during working hours and decide how to cover nights and weekends.
- Larger organisations with security teams typically need multiple source integration, custom detections and existing tool compatibility.
APPSEC supplies and supports SentinelOne for enterprise environments and Heimdal Security for smaller and medium-sized businesses. These are examples we work with; the same questions apply to any vendor.
Updates, MFA, backups and incident procedures remain essential. NIST Cybersecurity Framework 2.0 places detection and response among six core cybersecurity functions.
Selection checklist
- You know device and server types and quantities.
- Alert assessment ownership is clear inside and outside working hours.
- Required data sources and support are verified.
- Licensing, vendor services and supplier support are distinguished.
- Approval authority for actions such as server isolation is agreed.
- The pilot has defined success criteria.
- The solution fits incident response and recovery procedures.
Arrange a consultation to discuss which approach suits your environment. We distinguish recommendations from any subsequent product proposal.
