Do You Need EDR? A Small Business Decision Guide

Antivirus mainly compares files against known signatures and simple behavior rules and blocks matches. It's a preventive filter. EDR adds continuous recording of activity on the endpoint, such as processes launched, network connections and changes to files and the registry, and analyzes it for attack patterns.

That difference matters after something slips through. With EDR, you can see how an attacker got in, which accounts and machines they touched, and you can isolate a device from the network remotely. With antivirus alone, you may only know a file was quarantined, and have no idea what ran before it.

Use these questions to decide:

• Do employees access customer or financial data from laptops? If yes, lean toward EDR.
• Do you handle regulated data, or do customers require security controls in contracts? Often yes.
• Are you applying for or renewing cyber insurance? Many insurers ask about EDR, so check the questionnaire.
• Do you have fewer than a handful of devices, no sensitive data and only cloud apps? You may be fine starting with strong basics: managed devices, automatic patching, multi-factor authentication and backups.
• Do you have no one who can respond to alerts within a reasonable time? Choose a managed service or don't buy yet.

For most companies with staff and customer data, the answer is to get some form of EDR. The real decisions are which one and who watches it.

This is the question most buying processes skip. Consider three models:

1. You watch it: a technical owner triages alerts during business hours. It's cheapest, but attacks often begin out of hours.
2. Managed detection and response: the vendor or a partner staffs monitoring and either contains threats or calls you. It costs more, but it's usually the right fit if nobody on your team does security full-time.
3. Auto-contain only: the tool isolates devices automatically on high-confidence detections and emails you. It's a partial answer and can disrupt work with false positives.

Say you have 25 employees and one IT generalist. A managed service is probably worth the higher price, because the generalist can't watch a console at 3 a.m. Also decide who has authority to isolate a device, so you don't lose an hour asking permission.

Products such as CrowdStrike, SentinelOne and Microsoft Defender all sit in this category, and the three-way comparison helps you shortlist. In demos, ask for answers on your own situation, and confirm current details directly with each vendor:

• Which operating systems does it cover, including Mac and Linux if you have them?
• Is managed monitoring available, and what are its response times and scope?
• How does it fit with licenses you already own? If you're a Microsoft 365 shop, check which tier of Microsoft's endpoint protection your subscription already includes before buying anything additional.
• How are policies managed across laptops, and how does it handle devices that are offline?
• What's the effect on device performance, and can you run a pilot?

Get pricing in writing, including any minimum seat counts.

Also ask each vendor how a false positive is handled. A tool that quarantines a legitimate accounting application in the middle of month-end creates its own outage, so find out how exclusions are requested and how quickly they take effect.

Pilot on a small group of devices for a couple of weeks in detect-only mode, review the false positives and tune exclusions for legitimate tools. Then move to full protection in waves, IT devices first. Keep an inventory so you know which machines lack the agent. Alongside EDR, keep patching, since EDR doesn't replace it: CISA's federal directive BOD 19-02 sets 15 days for critical vulnerabilities on internet-accessible systems¹, a good benchmark to aim for. Finally, write down what happens when an alert fires, and rehearse it once with a short tabletop exercise.